public Builder mergeFrom(com.google.protobuf.Message other) {
          if (other instanceof com.google.protobuf.DescriptorProtos.DescriptorProto.ExtensionRange) {
            return mergeFrom((com.google.protobuf.DescriptorProtos.DescriptorProto.ExtensionRange)other);
          } else {
            super.mergeFrom(other);
            return this;
          }
        }