@java.lang.Override
  public void writeTo(com.google.protobuf.CodedOutputStream output) throws java.io.IOException {
    com.google.protobuf.GeneratedMessageV3.serializeStringMapTo(
        output, internalGetElements(), ElementsDefaultEntryHolder.defaultEntry, 2);
    getUnknownFields().writeTo(output);
  }
<pre>
A map from elements' keys to element's annotation value.
</pre>

<code>map&lt;string, .google.cloud.visionai.v1.AnnotationValue&gt; elements = 2;</code>
java-visionai/proto-google-cloud-visionai-v1/src/main/java/com/google/cloud/visionai/v1/AnnotationCustomizedStruct.java