code: public final void mT__16() throws RecognitionException {
          try {
              int _type = T__16;
              int _channel = DEFAULT_TOKEN_CHANNEL;
              // InternalXbase.g:14:7: ( '+=' )
              // InternalXbase.g:14:9: '+='
              {
              match("+="); 
  
  
              }
  
              state.type = _type;
              state.channel = _channel;
          }
          finally {
          }
      }
docs: $ANTLR start "T__16"