public Builder clearFormat() {
        format_ = getDefaultInstance().getFormat();
        bitField0_ = (bitField0_ & ~0x00000010);
        onChanged();
        return this;
      }
<pre>
avi, jpg, youtube, cnbc, audio/mpeg formats ...
</pre>

<code>string format = 5;</code>
@return This builder for chaining.
benchmark/src/main/java/com/alibaba/fastjson2/benchmark/protobuf/MediaContentHolder.java