private com.google.protobuf.SingleFieldBuilderV3<
              com.google.protobuf.Struct,
              com.google.protobuf.Struct.Builder,
              com.google.protobuf.StructOrBuilder>
          getAnnotationFieldBuilder() {
        if (annotationBuilder_ == null) {
          annotationBuilder_ =
              new com.google.protobuf.SingleFieldBuilderV3<
                  com.google.protobuf.Struct,
                  com.google.protobuf.Struct.Builder,
                  com.google.protobuf.StructOrBuilder>(
                  getAnnotation(), getParentForChildren(), isClean());
          annotation_ = null;
        }
        return annotationBuilder_;
      }
<pre>
The struct format of the actual annotation.
</pre>

<code>.google.protobuf.Struct annotation = 1;</code>
java-visionai/proto-google-cloud-visionai-v1/src/main/java/com/google/cloud/visionai/v1/AppPlatformCloudFunctionResponse.java