private com.google.protobuf.SingleFieldBuilderV3<
            com.google.cloud.vertexai.api.FunctionResponse,
            com.google.cloud.vertexai.api.FunctionResponse.Builder,
            com.google.cloud.vertexai.api.FunctionResponseOrBuilder>
        getFunctionResponseFieldBuilder() {
      if (functionResponseBuilder_ == null) {
        if (!(dataCase_ == 6)) {
          data_ = com.google.cloud.vertexai.api.FunctionResponse.getDefaultInstance();
        }
        functionResponseBuilder_ =
            new com.google.protobuf.SingleFieldBuilderV3<
                com.google.cloud.vertexai.api.FunctionResponse,
                com.google.cloud.vertexai.api.FunctionResponse.Builder,
                com.google.cloud.vertexai.api.FunctionResponseOrBuilder>(
                (com.google.cloud.vertexai.api.FunctionResponse) data_,
                getParentForChildren(),
                isClean());
        data_ = null;
      }
      dataCase_ = 6;
      onChanged();
      return functionResponseBuilder_;
    }
<pre>
Optional. The result output of a [FunctionCall] that contains a string
representing the [FunctionDeclaration.name] and a structured JSON object
containing any output from the function call. It is used as context to
the model.
</pre>

<code>
.google.cloud.vertexai.v1.FunctionResponse function_response = 6 [(.google.api.field_behavior) = OPTIONAL];
</code>
java-vertexai/proto-google-cloud-vertexai-v1/src/main/java/com/google/cloud/vertexai/api/Part.java