public Builder mergeFrom(com.google.protobuf.DescriptorProtos.FileDescriptorSet other) {
        if (other == getDefaultInstance()) return this;
        if (fileBuilder_ == null) {
          if (!other.file_.isEmpty()) {
            if (file_.isEmpty()) {
              file_ = other.file_;
              bitField0_ = (bitField0_ & ~0x00000001);
            } else {
              ensureFileIsMutable();
              file_.addAll(other.file_);
            }
            onChanged();
          }
        } else {
          if (!other.file_.isEmpty()) {
            if (fileBuilder_.isEmpty()) {
              fileBuilder_.dispose();
              fileBuilder_ = null;
              file_ = other.file_;
              bitField0_ = (bitField0_ & ~0x00000001);
              fileBuilder_ = 
                alwaysUseFieldBuilders ?
                   getFileFieldBuilder() : null;
            } else {
              fileBuilder_.addAllMessages(other.file_);
            }
          }
        }
        this.mergeUnknownFields(other.getUnknownFields());
        return this;
      }