@java.lang.Override
  public int hashCode() {
    if (memoizedHashCode != 0) {
      return memoizedHashCode;
    }
    int hash = 41;
    hash = (19 * hash) + getDescriptor().hashCode();
    if (getCandidatesCount() > 0) {
      hash = (37 * hash) + CANDIDATES_FIELD_NUMBER;
      hash = (53 * hash) + getCandidatesList().hashCode();
    }
    hash = (37 * hash) + MODEL_VERSION_FIELD_NUMBER;
    hash = (53 * hash) + getModelVersion().hashCode();
    if (hasCreateTime()) {
      hash = (37 * hash) + CREATE_TIME_FIELD_NUMBER;
      hash = (53 * hash) + getCreateTime().hashCode();
    }
    hash = (37 * hash) + RESPONSE_ID_FIELD_NUMBER;
    hash = (53 * hash) + getResponseId().hashCode();
    if (hasPromptFeedback()) {
      hash = (37 * hash) + PROMPT_FEEDBACK_FIELD_NUMBER;
      hash = (53 * hash) + getPromptFeedback().hashCode();
    }
    if (hasUsageMetadata()) {
      hash = (37 * hash) + USAGE_METADATA_FIELD_NUMBER;
      hash = (53 * hash) + getUsageMetadata().hashCode();
    }
    hash = (29 * hash) + getUnknownFields().hashCode();
    memoizedHashCode = hash;
    return hash;
  }
<pre>
Usage metadata about the response(s).
</pre>

<code>.google.cloud.vertexai.v1.GenerateContentResponse.UsageMetadata usage_metadata = 4;
</code>
java-vertexai/proto-google-cloud-vertexai-v1/src/main/java/com/google/cloud/vertexai/api/GenerateContentResponse.java