public Builder mergeServerMetadata(com.google.cloud.visionai.v1.ServerMetadata value) {
      if (serverMetadataBuilder_ == null) {
        if (((bitField0_ & 0x00000008) != 0)
            && serverMetadata_ != null
            && serverMetadata_
                != com.google.cloud.visionai.v1.ServerMetadata.getDefaultInstance()) {
          getServerMetadataBuilder().mergeFrom(value);
        } else {
          serverMetadata_ = value;
        }
      } else {
        serverMetadataBuilder_.mergeFrom(value);
      }
      if (serverMetadata_ != null) {
        bitField0_ |= 0x00000008;
        onChanged();
      }
      return this;
    }
<pre>
Output only. Metadata that the server appends to each packet before sending
it to receivers. You don't need to set a value for this field when sending
packets.
</pre>

<code>
.google.cloud.visionai.v1.ServerMetadata server_metadata = 4 [(.google.api.field_behavior) = OUTPUT_ONLY];
</code>
java-visionai/proto-google-cloud-visionai-v1/src/main/java/com/google/cloud/visionai/v1/PacketHeader.java