public Builder setUpdateTime(com.google.protobuf.Timestamp value) {
      if (updateTimeBuilder_ == null) {
        if (value == null) {
          throw new NullPointerException();
        }
        updateTime_ = value;
      } else {
        updateTimeBuilder_.setMessage(value);
      }
      bitField0_ |= 0x00000004;
      onChanged();
      return this;
    }
<pre>
The last update time of the operation.
</pre>

<code>.google.protobuf.Timestamp update_time = 3;</code>
java-translate/proto-google-cloud-translate-v3/src/main/java/com/google/cloud/translate/v3/ImportDataMetadata.java