@java.lang.Override
    public final Builder mergeUnknownFields(
        final com.google.protobuf.UnknownFieldSet unknownFields) {
      return super.mergeUnknownFields(unknownFields);
    }
<pre>
The time when the operation result was last updated.
</pre>

<code>.google.protobuf.Timestamp update_time = 6;</code>
java-vision/proto-google-cloud-vision-v1/src/main/java/com/google/cloud/vision/v1/OperationMetadata.java