public com.google.protobuf.FieldMask getUpdateMask() {
      if (updateMaskBuilder_ == null) {
        return updateMask_ == null
            ? com.google.protobuf.FieldMask.getDefaultInstance()
            : updateMask_;
      } else {
        return updateMaskBuilder_.getMessage();
      }
    }
<pre>
Required. Mask of fields from [Node][Tpu.Node] to update.
Supported fields: [description, tags, labels, metadata,
network_config.enable_external_ips].
</pre>

<code>.google.protobuf.FieldMask update_mask = 1 [(.google.api.field_behavior) = REQUIRED];
</code>

@return The updateMask.
java-tpu/proto-google-cloud-tpu-v2/src/main/java/com/google/cloud/tpu/v2/UpdateNodeRequest.java