public com.google.protobuf.FieldMask.Builder getUpdateMaskBuilder() {
      bitField0_ |= 0x00000004;
      onChanged();
      return getUpdateMaskFieldBuilder().getBuilder();
    }
<pre>
Required. The update mask applies to the resource. See
[google.protobuf.FieldMask][google.protobuf.FieldMask].
</pre>

<code>.google.protobuf.FieldMask update_mask = 4 [(.google.api.field_behavior) = REQUIRED];
</code>
java-vertexai/proto-google-cloud-vertexai-v1/src/main/java/com/google/cloud/vertexai/api/MutateDeployedModelRequest.java