public com.google.protobuf.FieldMask getUpdateMask() {
      if (updateMaskBuilder_ == null) {
        return updateMask_ == null
            ? com.google.protobuf.FieldMask.getDefaultInstance()
            : updateMask_;
      } else {
        return updateMaskBuilder_.getMessage();
      }
    }
<pre>
Required. Update mask is used to specify the fields to be overwritten in
the `blueprint` resource by the update.
</pre>

<code>.google.protobuf.FieldMask update_mask = 2 [(.google.api.field_behavior) = REQUIRED];
</code>

@return The updateMask.
java-telcoautomation/proto-google-cloud-telcoautomation-v1alpha1/src/main/java/com/google/cloud/telcoautomation/v1alpha1/UpdateBlueprintRequest.java