public com.google.protobuf.Timestamp.Builder getUpdateTimeBuilder() {
      bitField0_ |= 0x00000020;
      onChanged();
      return getUpdateTimeFieldBuilder().getBuilder();
    }
<pre>
Output only. The last update timestamp of the workflow.
</pre>

<code>
.google.protobuf.Timestamp update_time = 6 [(.google.api.field_behavior) = OUTPUT_ONLY];
</code>
java-workflows/proto-google-cloud-workflows-v1beta/src/main/java/com/google/cloud/workflows/v1beta/Workflow.java