@java.lang.Override
    public java.lang.String getFormat() {
      java.lang.Object ref = format_;
      if (ref instanceof java.lang.String) {
        return (java.lang.String) ref;
      } else {
        com.google.protobuf.ByteString bs =
            (com.google.protobuf.ByteString) ref;
        java.lang.String s = bs.toStringUtf8();
        format_ = s;
        return s;
      }
    }
<pre>
avi, jpg, youtube, cnbc, audio/mpeg formats ...
</pre>

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