diff --git a/protobuf/gen/cc/tutorial/addressbook.pb.cc b/protobuf/gen/cc/tutorial/addressbook.pb.cc
index 9b34141..50f0a05 100644
--- a/protobuf/gen/cc/tutorial/addressbook.pb.cc
+++ b/protobuf/gen/cc/tutorial/addressbook.pb.cc
@@ -27,6 +27,7 @@ const ::google::protobuf::EnumDescriptor* Person_PhoneType_descriptor_ = NULL;
 const ::google::protobuf::Descriptor* AddressBook_descriptor_ = NULL;
 const ::google::protobuf::internal::GeneratedMessageReflection*
   AddressBook_reflection_ = NULL;
+const ::google::protobuf::EnumDescriptor* Gender_descriptor_ = NULL;
 
 }  // namespace
 
@@ -38,10 +39,11 @@ void protobuf_AssignDesc_addressbook_2eproto() {
       "addressbook.proto");
   GOOGLE_CHECK(file != NULL);
   Person_descriptor_ = file->message_type(0);
-  static const int Person_offsets_[4] = {
+  static const int Person_offsets_[5] = {
     GOOGLE_PROTOBUF_GENERATED_MESSAGE_FIELD_OFFSET(Person, name_),
     GOOGLE_PROTOBUF_GENERATED_MESSAGE_FIELD_OFFSET(Person, id_),
     GOOGLE_PROTOBUF_GENERATED_MESSAGE_FIELD_OFFSET(Person, email_),
+    GOOGLE_PROTOBUF_GENERATED_MESSAGE_FIELD_OFFSET(Person, type_),
     GOOGLE_PROTOBUF_GENERATED_MESSAGE_FIELD_OFFSET(Person, phone_),
   };
   Person_reflection_ =
@@ -87,6 +89,7 @@ void protobuf_AssignDesc_addressbook_2eproto() {
       ::google::protobuf::DescriptorPool::generated_pool(),
       ::google::protobuf::MessageFactory::generated_factory(),
       sizeof(AddressBook));
+  Gender_descriptor_ = file->enum_type(0);
 }
 
 namespace {
@@ -125,14 +128,16 @@ void protobuf_AddDesc_addressbook_2eproto() {
   GOOGLE_PROTOBUF_VERIFY_VERSION;
 
   ::google::protobuf::DescriptorPool::InternalAddGeneratedFile(
-    "\n\021addressbook.proto\022\010tutorial\"\332\001\n\006Person"
+    "\n\021addressbook.proto\022\010tutorial\"\200\002\n\006Person"
     "\022\014\n\004name\030\001 \002(\t\022\n\n\002id\030\002 \002(\005\022\r\n\005email\030\003 \001("
-    "\t\022+\n\005phone\030\004 \003(\0132\034.tutorial.Person.Phone"
-    "Number\032M\n\013PhoneNumber\022\016\n\006number\030\001 \002(\t\022.\n"
-    "\004type\030\002 \001(\0162\032.tutorial.Person.PhoneType:"
-    "\004HOME\"+\n\tPhoneType\022\n\n\006MOBILE\020\000\022\010\n\004HOME\020\001"
-    "\022\010\n\004WORK\020\002\"/\n\013AddressBook\022 \n\006person\030\001 \003("
-    "\0132\020.tutorial.Person", 299);
+    "\t\022$\n\004type\030\004 \001(\0162\020.tutorial.Gender:\004NONE\022"
+    "+\n\005phone\030\005 \003(\0132\034.tutorial.Person.PhoneNu"
+    "mber\032M\n\013PhoneNumber\022\016\n\006number\030\001 \002(\t\022.\n\004t"
+    "ype\030\002 \001(\0162\032.tutorial.Person.PhoneType:\004H"
+    "OME\"+\n\tPhoneType\022\n\n\006MOBILE\020\000\022\010\n\004HOME\020\001\022\010"
+    "\n\004WORK\020\002\"/\n\013AddressBook\022 \n\006person\030\001 \003(\0132"
+    "\020.tutorial.Person*3\n\006Gender\022\010\n\004NONE\020\000\022\010\n"
+    "\004MALE\020\001\022\n\n\006FEMALE\020\002\022\t\n\005OTHER\020\003", 390);
   ::google::protobuf::MessageFactory::InternalRegisterGeneratedFile(
     "addressbook.proto", &protobuf_RegisterTypes);
   Person::default_instance_ = new Person();
@@ -151,6 +156,22 @@ struct StaticDescriptorInitializer_addressbook_2eproto {
   }
 } static_descriptor_initializer_addressbook_2eproto_;
 
+const ::google::protobuf::EnumDescriptor* Gender_descriptor() {
+  protobuf_AssignDescriptorsOnce();
+  return Gender_descriptor_;
+}
+bool Gender_IsValid(int value) {
+  switch(value) {
+    case 0:
+    case 1:
+    case 2:
+    case 3:
+      return true;
+    default:
+      return false;
+  }
+}
+
 
 // ===================================================================
 
@@ -452,6 +473,7 @@ void Person_PhoneNumber::Swap(Person_PhoneNumber* other) {
 const int Person::kNameFieldNumber;
 const int Person::kIdFieldNumber;
 const int Person::kEmailFieldNumber;
+const int Person::kTypeFieldNumber;
 const int Person::kPhoneFieldNumber;
 #endif  // !_MSC_VER
 
@@ -474,6 +496,7 @@ void Person::SharedCtor() {
   name_ = const_cast< ::std::string*>(&::google::protobuf::internal::kEmptyString);
   id_ = 0;
   email_ = const_cast< ::std::string*>(&::google::protobuf::internal::kEmptyString);
+  type_ = 0;
   ::memset(_has_bits_, 0, sizeof(_has_bits_));
 }
 
@@ -525,6 +548,7 @@ void Person::Clear() {
         email_->clear();
       }
     }
+    type_ = 0;
   }
   phone_.Clear();
   ::memset(_has_bits_, 0, sizeof(_has_bits_));
@@ -582,12 +606,33 @@ bool Person::MergePartialFromCodedStream(
         } else {
           goto handle_uninterpreted;
         }
-        if (input->ExpectTag(34)) goto parse_phone;
+        if (input->ExpectTag(32)) goto parse_type;
         break;
       }
       
-      // repeated .tutorial.Person.PhoneNumber phone = 4;
+      // optional .tutorial.Gender type = 4 [default = NONE];
       case 4: {
+        if (::google::protobuf::internal::WireFormatLite::GetTagWireType(tag) ==
+            ::google::protobuf::internal::WireFormatLite::WIRETYPE_VARINT) {
+         parse_type:
+          int value;
+          DO_((::google::protobuf::internal::WireFormatLite::ReadPrimitive<
+                   int, ::google::protobuf::internal::WireFormatLite::TYPE_ENUM>(
+                 input, &value)));
+          if (tutorial::Gender_IsValid(value)) {
+            set_type(static_cast< tutorial::Gender >(value));
+          } else {
+            mutable_unknown_fields()->AddVarint(4, value);
+          }
+        } else {
+          goto handle_uninterpreted;
+        }
+        if (input->ExpectTag(42)) goto parse_phone;
+        break;
+      }
+      
+      // repeated .tutorial.Person.PhoneNumber phone = 5;
+      case 5: {
         if (::google::protobuf::internal::WireFormatLite::GetTagWireType(tag) ==
             ::google::protobuf::internal::WireFormatLite::WIRETYPE_LENGTH_DELIMITED) {
          parse_phone:
@@ -596,7 +641,7 @@ bool Person::MergePartialFromCodedStream(
         } else {
           goto handle_uninterpreted;
         }
-        if (input->ExpectTag(34)) goto parse_phone;
+        if (input->ExpectTag(42)) goto parse_phone;
         if (input->ExpectAtEnd()) return true;
         break;
       }
@@ -642,10 +687,16 @@ void Person::SerializeWithCachedSizes(
       3, this->email(), output);
   }
   
-  // repeated .tutorial.Person.PhoneNumber phone = 4;
+  // optional .tutorial.Gender type = 4 [default = NONE];
+  if (has_type()) {
+    ::google::protobuf::internal::WireFormatLite::WriteEnum(
+      4, this->type(), output);
+  }
+  
+  // repeated .tutorial.Person.PhoneNumber phone = 5;
   for (int i = 0; i < this->phone_size(); i++) {
     ::google::protobuf::internal::WireFormatLite::WriteMessageMaybeToArray(
-      4, this->phone(i), output);
+      5, this->phone(i), output);
   }
   
   if (!unknown_fields().empty()) {
@@ -681,11 +732,17 @@ void Person::SerializeWithCachedSizes(
         3, this->email(), target);
   }
   
-  // repeated .tutorial.Person.PhoneNumber phone = 4;
+  // optional .tutorial.Gender type = 4 [default = NONE];
+  if (has_type()) {
+    target = ::google::protobuf::internal::WireFormatLite::WriteEnumToArray(
+      4, this->type(), target);
+  }
+  
+  // repeated .tutorial.Person.PhoneNumber phone = 5;
   for (int i = 0; i < this->phone_size(); i++) {
     target = ::google::protobuf::internal::WireFormatLite::
       WriteMessageNoVirtualToArray(
-        4, this->phone(i), target);
+        5, this->phone(i), target);
   }
   
   if (!unknown_fields().empty()) {
@@ -720,8 +777,14 @@ int Person::ByteSize() const {
           this->email());
     }
     
+    // optional .tutorial.Gender type = 4 [default = NONE];
+    if (has_type()) {
+      total_size += 1 +
+        ::google::protobuf::internal::WireFormatLite::EnumSize(this->type());
+    }
+    
   }
-  // repeated .tutorial.Person.PhoneNumber phone = 4;
+  // repeated .tutorial.Person.PhoneNumber phone = 5;
   total_size += 1 * this->phone_size();
   for (int i = 0; i < this->phone_size(); i++) {
     total_size +=
@@ -765,6 +828,9 @@ void Person::MergeFrom(const Person& from) {
     if (from.has_email()) {
       set_email(from.email());
     }
+    if (from.has_type()) {
+      set_type(from.type());
+    }
   }
   mutable_unknown_fields()->MergeFrom(from.unknown_fields());
 }
@@ -795,6 +861,7 @@ void Person::Swap(Person* other) {
     std::swap(name_, other->name_);
     std::swap(id_, other->id_);
     std::swap(email_, other->email_);
+    std::swap(type_, other->type_);
     phone_.Swap(&other->phone_);
     std::swap(_has_bits_[0], other->_has_bits_[0]);
     _unknown_fields_.Swap(&other->_unknown_fields_);
diff --git a/protobuf/gen/cc/tutorial/addressbook.pb.h b/protobuf/gen/cc/tutorial/addressbook.pb.h
index 479a1fa..2f5f34f 100644
--- a/protobuf/gen/cc/tutorial/addressbook.pb.h
+++ b/protobuf/gen/cc/tutorial/addressbook.pb.h
@@ -56,6 +56,27 @@ inline bool Person_PhoneType_Parse(
   return ::google::protobuf::internal::ParseNamedEnum<Person_PhoneType>(
     Person_PhoneType_descriptor(), name, value);
 }
+enum Gender {
+  NONE = 0,
+  MALE = 1,
+  FEMALE = 2,
+  OTHER = 3
+};
+bool Gender_IsValid(int value);
+const Gender Gender_MIN = NONE;
+const Gender Gender_MAX = OTHER;
+const int Gender_ARRAYSIZE = Gender_MAX + 1;
+
+const ::google::protobuf::EnumDescriptor* Gender_descriptor();
+inline const ::std::string& Gender_Name(Gender value) {
+  return ::google::protobuf::internal::NameOfEnum(
+    Gender_descriptor(), value);
+}
+inline bool Gender_Parse(
+    const ::std::string& name, Gender* value) {
+  return ::google::protobuf::internal::ParseNamedEnum<Gender>(
+    Gender_descriptor(), name, value);
+}
 // ===================================================================
 
 class Person_PhoneNumber : public ::google::protobuf::Message {
@@ -264,10 +285,17 @@ class Person : public ::google::protobuf::Message {
   inline ::std::string* mutable_email();
   inline ::std::string* release_email();
   
-  // repeated .tutorial.Person.PhoneNumber phone = 4;
+  // optional .tutorial.Gender type = 4 [default = NONE];
+  inline bool has_type() const;
+  inline void clear_type();
+  static const int kTypeFieldNumber = 4;
+  inline tutorial::Gender type() const;
+  inline void set_type(tutorial::Gender value);
+  
+  // repeated .tutorial.Person.PhoneNumber phone = 5;
   inline int phone_size() const;
   inline void clear_phone();
-  static const int kPhoneFieldNumber = 4;
+  static const int kPhoneFieldNumber = 5;
   inline const ::tutorial::Person_PhoneNumber& phone(int index) const;
   inline ::tutorial::Person_PhoneNumber* mutable_phone(int index);
   inline ::tutorial::Person_PhoneNumber* add_phone();
@@ -284,16 +312,19 @@ class Person : public ::google::protobuf::Message {
   inline void clear_has_id();
   inline void set_has_email();
   inline void clear_has_email();
+  inline void set_has_type();
+  inline void clear_has_type();
   
   ::google::protobuf::UnknownFieldSet _unknown_fields_;
   
   ::std::string* name_;
   ::std::string* email_;
-  ::google::protobuf::RepeatedPtrField< ::tutorial::Person_PhoneNumber > phone_;
   ::google::protobuf::int32 id_;
+  int type_;
+  ::google::protobuf::RepeatedPtrField< ::tutorial::Person_PhoneNumber > phone_;
   
   mutable int _cached_size_;
-  ::google::protobuf::uint32 _has_bits_[(4 + 31) / 32];
+  ::google::protobuf::uint32 _has_bits_[(5 + 31) / 32];
   
   friend void  protobuf_AddDesc_addressbook_2eproto();
   friend void protobuf_AssignDesc_addressbook_2eproto();
@@ -617,7 +648,30 @@ inline ::std::string* Person::release_email() {
   }
 }
 
-// repeated .tutorial.Person.PhoneNumber phone = 4;
+// optional .tutorial.Gender type = 4 [default = NONE];
+inline bool Person::has_type() const {
+  return (_has_bits_[0] & 0x00000008u) != 0;
+}
+inline void Person::set_has_type() {
+  _has_bits_[0] |= 0x00000008u;
+}
+inline void Person::clear_has_type() {
+  _has_bits_[0] &= ~0x00000008u;
+}
+inline void Person::clear_type() {
+  type_ = 0;
+  clear_has_type();
+}
+inline tutorial::Gender Person::type() const {
+  return static_cast< tutorial::Gender >(type_);
+}
+inline void Person::set_type(tutorial::Gender value) {
+  GOOGLE_DCHECK(tutorial::Gender_IsValid(value));
+  set_has_type();
+  type_ = value;
+}
+
+// repeated .tutorial.Person.PhoneNumber phone = 5;
 inline int Person::phone_size() const {
   return phone_.size();
 }
@@ -684,6 +738,10 @@ template <>
 inline const EnumDescriptor* GetEnumDescriptor< ::tutorial::Person_PhoneType>() {
   return ::tutorial::Person_PhoneType_descriptor();
 }
+template <>
+inline const EnumDescriptor* GetEnumDescriptor< tutorial::Gender>() {
+  return tutorial::Gender_descriptor();
+}
 
 }  // namespace google
 }  // namespace protobuf
diff --git a/protobuf/gen/java/tutorial/addressbook.java b/protobuf/gen/java/tutorial/addressbook.java
index bbd7fbb..999c143 100644
--- a/protobuf/gen/java/tutorial/addressbook.java
+++ b/protobuf/gen/java/tutorial/addressbook.java
@@ -8,6 +8,81 @@ public final class Addressbook {
   public static void registerAllExtensions(
       com.google.protobuf.ExtensionRegistry registry) {
   }
+  public enum Gender
+      implements com.google.protobuf.ProtocolMessageEnum {
+    NONE(0, 0),
+    MALE(1, 1),
+    FEMALE(2, 2),
+    OTHER(3, 3),
+    ;
+    
+    public static final int NONE_VALUE = 0;
+    public static final int MALE_VALUE = 1;
+    public static final int FEMALE_VALUE = 2;
+    public static final int OTHER_VALUE = 3;
+    
+    
+    public final int getNumber() { return value; }
+    
+    public static Gender valueOf(int value) {
+      switch (value) {
+        case 0: return NONE;
+        case 1: return MALE;
+        case 2: return FEMALE;
+        case 3: return OTHER;
+        default: return null;
+      }
+    }
+    
+    public static com.google.protobuf.Internal.EnumLiteMap<Gender>
+        internalGetValueMap() {
+      return internalValueMap;
+    }
+    private static com.google.protobuf.Internal.EnumLiteMap<Gender>
+        internalValueMap =
+          new com.google.protobuf.Internal.EnumLiteMap<Gender>() {
+            public Gender findValueByNumber(int number) {
+              return Gender.valueOf(number);
+            }
+          };
+    
+    public final com.google.protobuf.Descriptors.EnumValueDescriptor
+        getValueDescriptor() {
+      return getDescriptor().getValues().get(index);
+    }
+    public final com.google.protobuf.Descriptors.EnumDescriptor
+        getDescriptorForType() {
+      return getDescriptor();
+    }
+    public static final com.google.protobuf.Descriptors.EnumDescriptor
+        getDescriptor() {
+      return tutorial.Addressbook.getDescriptor().getEnumTypes().get(0);
+    }
+    
+    private static final Gender[] VALUES = {
+      NONE, MALE, FEMALE, OTHER, 
+    };
+    
+    public static Gender valueOf(
+        com.google.protobuf.Descriptors.EnumValueDescriptor desc) {
+      if (desc.getType() != getDescriptor()) {
+        throw new java.lang.IllegalArgumentException(
+          "EnumValueDescriptor is not for this type.");
+      }
+      return VALUES[desc.getIndex()];
+    }
+    
+    private final int index;
+    private final int value;
+    
+    private Gender(int index, int value) {
+      this.index = index;
+      this.value = value;
+    }
+    
+    // @@protoc_insertion_point(enum_scope:tutorial.Gender)
+  }
+  
   public interface PersonOrBuilder
       extends com.google.protobuf.MessageOrBuilder {
     
@@ -23,7 +98,11 @@ public final class Addressbook {
     boolean hasEmail();
     String getEmail();
     
-    // repeated .tutorial.Person.PhoneNumber phone = 4;
+    // optional .tutorial.Gender type = 4 [default = NONE];
+    boolean hasType();
+    tutorial.Addressbook.Gender getType();
+    
+    // repeated .tutorial.Person.PhoneNumber phone = 5;
     java.util.List<tutorial.Addressbook.Person.PhoneNumber> 
         getPhoneList();
     tutorial.Addressbook.Person.PhoneNumber getPhone(int index);
@@ -657,8 +736,18 @@ public final class Addressbook {
       }
     }
     
-    // repeated .tutorial.Person.PhoneNumber phone = 4;
-    public static final int PHONE_FIELD_NUMBER = 4;
+    // optional .tutorial.Gender type = 4 [default = NONE];
+    public static final int TYPE_FIELD_NUMBER = 4;
+    private tutorial.Addressbook.Gender type_;
+    public boolean hasType() {
+      return ((bitField0_ & 0x00000008) == 0x00000008);
+    }
+    public tutorial.Addressbook.Gender getType() {
+      return type_;
+    }
+    
+    // repeated .tutorial.Person.PhoneNumber phone = 5;
+    public static final int PHONE_FIELD_NUMBER = 5;
     private java.util.List<tutorial.Addressbook.Person.PhoneNumber> phone_;
     public java.util.List<tutorial.Addressbook.Person.PhoneNumber> getPhoneList() {
       return phone_;
@@ -682,6 +771,7 @@ public final class Addressbook {
       name_ = "";
       id_ = 0;
       email_ = "";
+      type_ = tutorial.Addressbook.Gender.NONE;
       phone_ = java.util.Collections.emptyList();
     }
     private byte memoizedIsInitialized = -1;
@@ -719,8 +809,11 @@ public final class Addressbook {
       if (((bitField0_ & 0x00000004) == 0x00000004)) {
         output.writeBytes(3, getEmailBytes());
       }
+      if (((bitField0_ & 0x00000008) == 0x00000008)) {
+        output.writeEnum(4, type_.getNumber());
+      }
       for (int i = 0; i < phone_.size(); i++) {
-        output.writeMessage(4, phone_.get(i));
+        output.writeMessage(5, phone_.get(i));
       }
       getUnknownFields().writeTo(output);
     }
@@ -743,9 +836,13 @@ public final class Addressbook {
         size += com.google.protobuf.CodedOutputStream
           .computeBytesSize(3, getEmailBytes());
       }
+      if (((bitField0_ & 0x00000008) == 0x00000008)) {
+        size += com.google.protobuf.CodedOutputStream
+          .computeEnumSize(4, type_.getNumber());
+      }
       for (int i = 0; i < phone_.size(); i++) {
         size += com.google.protobuf.CodedOutputStream
-          .computeMessageSize(4, phone_.get(i));
+          .computeMessageSize(5, phone_.get(i));
       }
       size += getUnknownFields().getSerializedSize();
       memoizedSerializedSize = size;
@@ -878,9 +975,11 @@ public final class Addressbook {
         bitField0_ = (bitField0_ & ~0x00000002);
         email_ = "";
         bitField0_ = (bitField0_ & ~0x00000004);
+        type_ = tutorial.Addressbook.Gender.NONE;
+        bitField0_ = (bitField0_ & ~0x00000008);
         if (phoneBuilder_ == null) {
           phone_ = java.util.Collections.emptyList();
-          bitField0_ = (bitField0_ & ~0x00000008);
+          bitField0_ = (bitField0_ & ~0x00000010);
         } else {
           phoneBuilder_.clear();
         }
@@ -934,10 +1033,14 @@ public final class Addressbook {
           to_bitField0_ |= 0x00000004;
         }
         result.email_ = email_;
+        if (((from_bitField0_ & 0x00000008) == 0x00000008)) {
+          to_bitField0_ |= 0x00000008;
+        }
+        result.type_ = type_;
         if (phoneBuilder_ == null) {
-          if (((bitField0_ & 0x00000008) == 0x00000008)) {
+          if (((bitField0_ & 0x00000010) == 0x00000010)) {
             phone_ = java.util.Collections.unmodifiableList(phone_);
-            bitField0_ = (bitField0_ & ~0x00000008);
+            bitField0_ = (bitField0_ & ~0x00000010);
           }
           result.phone_ = phone_;
         } else {
@@ -968,11 +1071,14 @@ public final class Addressbook {
         if (other.hasEmail()) {
           setEmail(other.getEmail());
         }
+        if (other.hasType()) {
+          setType(other.getType());
+        }
         if (phoneBuilder_ == null) {
           if (!other.phone_.isEmpty()) {
             if (phone_.isEmpty()) {
               phone_ = other.phone_;
-              bitField0_ = (bitField0_ & ~0x00000008);
+              bitField0_ = (bitField0_ & ~0x00000010);
             } else {
               ensurePhoneIsMutable();
               phone_.addAll(other.phone_);
@@ -985,7 +1091,7 @@ public final class Addressbook {
               phoneBuilder_.dispose();
               phoneBuilder_ = null;
               phone_ = other.phone_;
-              bitField0_ = (bitField0_ & ~0x00000008);
+              bitField0_ = (bitField0_ & ~0x00000010);
               phoneBuilder_ = 
                 com.google.protobuf.GeneratedMessage.alwaysUseFieldBuilders ?
                    getPhoneFieldBuilder() : null;
@@ -1054,7 +1160,18 @@ public final class Addressbook {
               email_ = input.readBytes();
               break;
             }
-            case 34: {
+            case 32: {
+              int rawValue = input.readEnum();
+              tutorial.Addressbook.Gender value = tutorial.Addressbook.Gender.valueOf(rawValue);
+              if (value == null) {
+                unknownFields.mergeVarintField(4, rawValue);
+              } else {
+                bitField0_ |= 0x00000008;
+                type_ = value;
+              }
+              break;
+            }
+            case 42: {
               tutorial.Addressbook.Person.PhoneNumber.Builder subBuilder = tutorial.Addressbook.Person.PhoneNumber.newBuilder();
               input.readMessage(subBuilder, extensionRegistry);
               addPhone(subBuilder.buildPartial());
@@ -1159,13 +1276,37 @@ public final class Addressbook {
         onChanged();
       }
       
-      // repeated .tutorial.Person.PhoneNumber phone = 4;
+      // optional .tutorial.Gender type = 4 [default = NONE];
+      private tutorial.Addressbook.Gender type_ = tutorial.Addressbook.Gender.NONE;
+      public boolean hasType() {
+        return ((bitField0_ & 0x00000008) == 0x00000008);
+      }
+      public tutorial.Addressbook.Gender getType() {
+        return type_;
+      }
+      public Builder setType(tutorial.Addressbook.Gender value) {
+        if (value == null) {
+          throw new NullPointerException();
+        }
+        bitField0_ |= 0x00000008;
+        type_ = value;
+        onChanged();
+        return this;
+      }
+      public Builder clearType() {
+        bitField0_ = (bitField0_ & ~0x00000008);
+        type_ = tutorial.Addressbook.Gender.NONE;
+        onChanged();
+        return this;
+      }
+      
+      // repeated .tutorial.Person.PhoneNumber phone = 5;
       private java.util.List<tutorial.Addressbook.Person.PhoneNumber> phone_ =
         java.util.Collections.emptyList();
       private void ensurePhoneIsMutable() {
-        if (!((bitField0_ & 0x00000008) == 0x00000008)) {
+        if (!((bitField0_ & 0x00000010) == 0x00000010)) {
           phone_ = new java.util.ArrayList<tutorial.Addressbook.Person.PhoneNumber>(phone_);
-          bitField0_ |= 0x00000008;
+          bitField0_ |= 0x00000010;
          }
       }
       
@@ -1281,7 +1422,7 @@ public final class Addressbook {
       public Builder clearPhone() {
         if (phoneBuilder_ == null) {
           phone_ = java.util.Collections.emptyList();
-          bitField0_ = (bitField0_ & ~0x00000008);
+          bitField0_ = (bitField0_ & ~0x00000010);
           onChanged();
         } else {
           phoneBuilder_.clear();
@@ -1337,7 +1478,7 @@ public final class Addressbook {
           phoneBuilder_ = new com.google.protobuf.RepeatedFieldBuilder<
               tutorial.Addressbook.Person.PhoneNumber, tutorial.Addressbook.Person.PhoneNumber.Builder, tutorial.Addressbook.Person.PhoneNumberOrBuilder>(
                   phone_,
-                  ((bitField0_ & 0x00000008) == 0x00000008),
+                  ((bitField0_ & 0x00000010) == 0x00000010),
                   getParentForChildren(),
                   isClean());
           phone_ = null;
@@ -1943,14 +2084,16 @@ public final class Addressbook {
       descriptor;
   static {
     java.lang.String[] descriptorData = {
-      "\n\021addressbook.proto\022\010tutorial\"\332\001\n\006Person" +
+      "\n\021addressbook.proto\022\010tutorial\"\200\002\n\006Person" +
       "\022\014\n\004name\030\001 \002(\t\022\n\n\002id\030\002 \002(\005\022\r\n\005email\030\003 \001(" +
-      "\t\022+\n\005phone\030\004 \003(\0132\034.tutorial.Person.Phone" +
-      "Number\032M\n\013PhoneNumber\022\016\n\006number\030\001 \002(\t\022.\n" +
-      "\004type\030\002 \001(\0162\032.tutorial.Person.PhoneType:" +
-      "\004HOME\"+\n\tPhoneType\022\n\n\006MOBILE\020\000\022\010\n\004HOME\020\001" +
-      "\022\010\n\004WORK\020\002\"/\n\013AddressBook\022 \n\006person\030\001 \003(" +
-      "\0132\020.tutorial.Person"
+      "\t\022$\n\004type\030\004 \001(\0162\020.tutorial.Gender:\004NONE\022" +
+      "+\n\005phone\030\005 \003(\0132\034.tutorial.Person.PhoneNu" +
+      "mber\032M\n\013PhoneNumber\022\016\n\006number\030\001 \002(\t\022.\n\004t" +
+      "ype\030\002 \001(\0162\032.tutorial.Person.PhoneType:\004H" +
+      "OME\"+\n\tPhoneType\022\n\n\006MOBILE\020\000\022\010\n\004HOME\020\001\022\010" +
+      "\n\004WORK\020\002\"/\n\013AddressBook\022 \n\006person\030\001 \003(\0132" +
+      "\020.tutorial.Person*3\n\006Gender\022\010\n\004NONE\020\000\022\010\n" +
+      "\004MALE\020\001\022\n\n\006FEMALE\020\002\022\t\n\005OTHER\020\003"
     };
     com.google.protobuf.Descriptors.FileDescriptor.InternalDescriptorAssigner assigner =
       new com.google.protobuf.Descriptors.FileDescriptor.InternalDescriptorAssigner() {
@@ -1962,7 +2105,7 @@ public final class Addressbook {
           internal_static_tutorial_Person_fieldAccessorTable = new
             com.google.protobuf.GeneratedMessage.FieldAccessorTable(
               internal_static_tutorial_Person_descriptor,
-              new java.lang.String[] { "Name", "Id", "Email", "Phone", },
+              new java.lang.String[] { "Name", "Id", "Email", "Type", "Phone", },
               tutorial.Addressbook.Person.class,
               tutorial.Addressbook.Person.Builder.class);
           internal_static_tutorial_Person_PhoneNumber_descriptor =
diff --git a/protobuf/gen/py/tutorial/addressbook_pb2.py b/protobuf/gen/py/tutorial/addressbook_pb2.py
index 4135ab6..19312ff 100644
--- a/protobuf/gen/py/tutorial/addressbook_pb2.py
+++ b/protobuf/gen/py/tutorial/addressbook_pb2.py
@@ -11,8 +11,42 @@ from google.protobuf import descriptor_pb2
 DESCRIPTOR = descriptor.FileDescriptor(
   name='addressbook.proto',
   package='tutorial',
-  serialized_pb='\n\x11\x61\x64\x64ressbook.proto\x12\x08tutorial\"\xda\x01\n\x06Person\x12\x0c\n\x04name\x18\x01 \x02(\t\x12\n\n\x02id\x18\x02 \x02(\x05\x12\r\n\x05\x65mail\x18\x03 \x01(\t\x12+\n\x05phone\x18\x04 \x03(\x0b\x32\x1c.tutorial.Person.PhoneNumber\x1aM\n\x0bPhoneNumber\x12\x0e\n\x06number\x18\x01 \x02(\t\x12.\n\x04type\x18\x02 \x01(\x0e\x32\x1a.tutorial.Person.PhoneType:\x04HOME\"+\n\tPhoneType\x12\n\n\x06MOBILE\x10\x00\x12\x08\n\x04HOME\x10\x01\x12\x08\n\x04WORK\x10\x02\"/\n\x0b\x41\x64\x64ressBook\x12 \n\x06person\x18\x01 \x03(\x0b\x32\x10.tutorial.Person')
+  serialized_pb='\n\x11\x61\x64\x64ressbook.proto\x12\x08tutorial\"\x80\x02\n\x06Person\x12\x0c\n\x04name\x18\x01 \x02(\t\x12\n\n\x02id\x18\x02 \x02(\x05\x12\r\n\x05\x65mail\x18\x03 \x01(\t\x12$\n\x04type\x18\x04 \x01(\x0e\x32\x10.tutorial.Gender:\x04NONE\x12+\n\x05phone\x18\x05 \x03(\x0b\x32\x1c.tutorial.Person.PhoneNumber\x1aM\n\x0bPhoneNumber\x12\x0e\n\x06number\x18\x01 \x02(\t\x12.\n\x04type\x18\x02 \x01(\x0e\x32\x1a.tutorial.Person.PhoneType:\x04HOME\"+\n\tPhoneType\x12\n\n\x06MOBILE\x10\x00\x12\x08\n\x04HOME\x10\x01\x12\x08\n\x04WORK\x10\x02\"/\n\x0b\x41\x64\x64ressBook\x12 \n\x06person\x18\x01 \x03(\x0b\x32\x10.tutorial.Person*3\n\x06Gender\x12\x08\n\x04NONE\x10\x00\x12\x08\n\x04MALE\x10\x01\x12\n\n\x06\x46\x45MALE\x10\x02\x12\t\n\x05OTHER\x10\x03')
 
+_GENDER = descriptor.EnumDescriptor(
+  name='Gender',
+  full_name='tutorial.Gender',
+  filename=None,
+  file=DESCRIPTOR,
+  values=[
+    descriptor.EnumValueDescriptor(
+      name='NONE', index=0, number=0,
+      options=None,
+      type=None),
+    descriptor.EnumValueDescriptor(
+      name='MALE', index=1, number=1,
+      options=None,
+      type=None),
+    descriptor.EnumValueDescriptor(
+      name='FEMALE', index=2, number=2,
+      options=None,
+      type=None),
+    descriptor.EnumValueDescriptor(
+      name='OTHER', index=3, number=3,
+      options=None,
+      type=None),
+  ],
+  containing_type=None,
+  options=None,
+  serialized_start=339,
+  serialized_end=390,
+)
+
+
+NONE = 0
+MALE = 1
+FEMALE = 2
+OTHER = 3
 
 
 _PERSON_PHONETYPE = descriptor.EnumDescriptor(
@@ -36,8 +70,8 @@ _PERSON_PHONETYPE = descriptor.EnumDescriptor(
   ],
   containing_type=None,
   options=None,
-  serialized_start=207,
-  serialized_end=250,
+  serialized_start=245,
+  serialized_end=288,
 )
 
 
@@ -71,8 +105,8 @@ _PERSON_PHONENUMBER = descriptor.Descriptor(
   options=None,
   is_extendable=False,
   extension_ranges=[],
-  serialized_start=128,
-  serialized_end=205,
+  serialized_start=166,
+  serialized_end=243,
 )
 
 _PERSON = descriptor.Descriptor(
@@ -104,8 +138,15 @@ _PERSON = descriptor.Descriptor(
       is_extension=False, extension_scope=None,
       options=None),
     descriptor.FieldDescriptor(
-      name='phone', full_name='tutorial.Person.phone', index=3,
-      number=4, type=11, cpp_type=10, label=3,
+      name='type', full_name='tutorial.Person.type', index=3,
+      number=4, type=14, cpp_type=8, label=1,
+      has_default_value=True, default_value=0,
+      message_type=None, enum_type=None, containing_type=None,
+      is_extension=False, extension_scope=None,
+      options=None),
+    descriptor.FieldDescriptor(
+      name='phone', full_name='tutorial.Person.phone', index=4,
+      number=5, type=11, cpp_type=10, label=3,
       has_default_value=False, default_value=[],
       message_type=None, enum_type=None, containing_type=None,
       is_extension=False, extension_scope=None,
@@ -121,7 +162,7 @@ _PERSON = descriptor.Descriptor(
   is_extendable=False,
   extension_ranges=[],
   serialized_start=32,
-  serialized_end=250,
+  serialized_end=288,
 )
 
 
@@ -148,12 +189,13 @@ _ADDRESSBOOK = descriptor.Descriptor(
   options=None,
   is_extendable=False,
   extension_ranges=[],
-  serialized_start=252,
-  serialized_end=299,
+  serialized_start=290,
+  serialized_end=337,
 )
 
 _PERSON_PHONENUMBER.fields_by_name['type'].enum_type = _PERSON_PHONETYPE
 _PERSON_PHONENUMBER.containing_type = _PERSON;
+_PERSON.fields_by_name['type'].enum_type = _GENDER
 _PERSON.fields_by_name['phone'].message_type = _PERSON_PHONENUMBER
 _PERSON_PHONETYPE.containing_type = _PERSON;
 _ADDRESSBOOK.fields_by_name['person'].message_type = _PERSON
diff --git a/protobuf/src/tutorial/addressbook.proto b/protobuf/src/tutorial/addressbook.proto
index bb87f1a..bb7bd3f 100644
--- a/protobuf/src/tutorial/addressbook.proto
+++ b/protobuf/src/tutorial/addressbook.proto
@@ -1,9 +1,17 @@
 package tutorial;
 
+enum Gender {
+    NONE = 0;
+    MALE = 1;
+    FEMALE = 2;
+    OTHER = 3;
+}
+
 message Person {
     required string name = 1;
     required int32 id = 2;
     optional string email = 3;
+    optional Gender type = 4 [default = NONE];
 
     enum PhoneType {
         MOBILE = 0;
@@ -16,7 +24,7 @@ message Person {
         optional PhoneType type = 2 [default = HOME];
     }
 
-    repeated PhoneNumber phone = 4;
+    repeated PhoneNumber phone = 5;
 }
 
 message AddressBook {