public Builder clearCard() {
        if (cardBuilder_ == null) {
          card_ = null;
          onChanged();
        } else {
          card_ = null;
          cardBuilder_ = null;
        }

        return this;
      }
<code>.com.alibaba.fastjson2.dubbo.DriverCard card = 16;</code>
core/src/test/java/com/alibaba/fastjson2/dubbo/GoogleProtobufBasic.java