public Builder clearMetadata() {
      if (metadataBuilder_ == null) {
        if (requestCase_ == 2) {
          requestCase_ = 0;
          request_ = null;
          onChanged();
        }
      } else {
        if (requestCase_ == 2) {
          requestCase_ = 0;
          request_ = null;
        }
        metadataBuilder_.clear();
      }
      return this;
    }
<pre>
The first message of the streaming rpc including the request metadata.
</pre>

<code>.google.cloud.visionai.v1.RequestMetadata metadata = 2;</code>
java-visionai/proto-google-cloud-visionai-v1/src/main/java/com/google/cloud/visionai/v1/SendPacketsRequest.java