public Builder mergeAuthentication(protocols.ChatProtocol.Authentication value) {
        if (authenticationBuilder_ == null) {
          if (((bitField0_ & 0x00000008) == 0x00000008) &&
              authentication_ != protocols.ChatProtocol.Authentication.getDefaultInstance()) {
            authentication_ =
              protocols.ChatProtocol.Authentication.newBuilder(authentication_).mergeFrom(value).buildPartial();
          } else {
            authentication_ = value;
          }
          onChanged();
        } else {
          authenticationBuilder_.mergeFrom(value);
        }
        bitField0_ |= 0x00000008;
        return this;
      }