public Builder setString(
          String value) {
        if (value == null) {
    throw new NullPointerException();
  }

        string_ = value;
        onChanged();
        return this;
      }
<code>string string = 14;</code>
@param value The string to set.
@return This builder for chaining.
core/src/test/java/com/alibaba/fastjson2/dubbo/GoogleProtobufBasic.java