@java.lang.Override
  public void writeTo(com.google.protobuf.CodedOutputStream output) throws java.io.IOException {
    for (int i = 0; i < predictions_.size(); i++) {
      output.writeMessage(1, predictions_.get(i));
    }
    if (!com.google.protobuf.GeneratedMessageV3.isStringEmpty(deployedModelId_)) {
      com.google.protobuf.GeneratedMessageV3.writeString(output, 2, deployedModelId_);
    }
    if (!com.google.protobuf.GeneratedMessageV3.isStringEmpty(model_)) {
      com.google.protobuf.GeneratedMessageV3.writeString(output, 3, model_);
    }
    if (!com.google.protobuf.GeneratedMessageV3.isStringEmpty(modelDisplayName_)) {
      com.google.protobuf.GeneratedMessageV3.writeString(output, 4, modelDisplayName_);
    }
    if (!com.google.protobuf.GeneratedMessageV3.isStringEmpty(modelVersionId_)) {
      com.google.protobuf.GeneratedMessageV3.writeString(output, 5, modelVersionId_);
    }
    if (((bitField0_ & 0x00000001) != 0)) {
      output.writeMessage(6, getMetadata());
    }
    getUnknownFields().writeTo(output);
  }
<pre>
Output only. Request-level metadata returned by the model. The metadata
type will be dependent upon the model implementation.
</pre>

<code>.google.protobuf.Value metadata = 6 [(.google.api.field_behavior) = OUTPUT_ONLY];</code>
java-vertexai/proto-google-cloud-vertexai-v1/src/main/java/com/google/cloud/vertexai/api/PredictResponse.java