private com.google.protobuf.SingleFieldBuilderV3<
            com.google.cloud.visionai.v1.OperationMetadata,
            com.google.cloud.visionai.v1.OperationMetadata.Builder,
            com.google.cloud.visionai.v1.OperationMetadataOrBuilder>
        getOperationMetadataFieldBuilder() {
      if (operationMetadataBuilder_ == null) {
        operationMetadataBuilder_ =
            new com.google.protobuf.SingleFieldBuilderV3<
                com.google.cloud.visionai.v1.OperationMetadata,
                com.google.cloud.visionai.v1.OperationMetadata.Builder,
                com.google.cloud.visionai.v1.OperationMetadataOrBuilder>(
                getOperationMetadata(), getParentForChildren(), isClean());
        operationMetadata_ = null;
      }
      return operationMetadataBuilder_;
    }
<pre>
Common metadata of the long-running operation.
</pre>

<code>.google.cloud.visionai.v1.OperationMetadata operation_metadata = 1;</code>
java-visionai/proto-google-cloud-visionai-v1/src/main/java/com/google/cloud/visionai/v1/DeleteCollectionMetadata.java