@java.lang.Override
  public com.google.protobuf.FieldMask getUpdateMask() {
    return updateMask_ == null ? com.google.protobuf.FieldMask.getDefaultInstance() : updateMask_;
  }
<pre>
The [FieldMask][google.protobuf.FieldMask] that specifies which fields to
update.
If update_mask isn't specified, all mutable fields are to be updated.
Valid mask path is `display_name`.
</pre>

<code>.google.protobuf.FieldMask update_mask = 2;</code>

@return The updateMask.
java-vision/proto-google-cloud-vision-v1/src/main/java/com/google/cloud/vision/v1/UpdateProductSetRequest.java