text: // Protocol Buffers for Objective C
  //
  // Copyright 2010 Booyah Inc.
  // Copyright 2008 Cyrus Najmabadi
  //
  // Licensed under the Apache License, Version 2.0 (the "License");
  // you may not use this file except in compliance with the License.
  // You may obtain a copy of the License at
  //
  //      http://www.apache.org/licenses/LICENSE-2.0
  //
  // Unless required by applicable law or agreed to in writing, software
  // distributed under the License is distributed on an "AS IS" BASIS,
  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  // See the License for the specific language governing permissions and
  // limitations under the License.
  
  #import "WireFormat.h"
  
  @class PBCodedInputStream;
  @class PBCodedOutputStream;
  @class PBExtendableMessageBuilder;
  @class PBExtensionRegistry;
  @class PBUnknownFieldSetBuilder;
  
  @protocol PBExtensionField
  - (SInt32) fieldNumber;
  - (PBWireFormat) wireType;
  - (BOOL) isRepeated;
  - (Class) extendedClass;
  - (instancetype) defaultValue;
  
  - (void) mergeFromCodedInputStream:(PBCodedInputStream*) input
                       unknownFields:(PBUnknownFieldSetBuilder*) unknownFields
                   extensionRegistry:(PBExtensionRegistry*) extensionRegistry
                             builder:(PBExtendableMessageBuilder*) builder
                                 tag:(SInt32) tag;
  - (void) writeValue:(id) value includingTagToCodedOutputStream:(PBCodedOutputStream*) output;
  - (SInt32) computeSerializedSizeIncludingTag:(id) value;
  - (void) writeDescriptionOf:(id) value
                           to:(NSMutableString*) output
                   withIndent:(NSString*) indent;
  - (void) addDictionaryEntriesOf:(id) value
                               to:(NSMutableDictionary*) dictionary;
  @end
  