public final int getNumber() {
          if (this == UNRECOGNIZED) {
            throw new java.lang.IllegalArgumentException(
                "Can't get the number of an unknown enum value.");
          }
          return value;
        }
<pre>
The attributions are used as a mask to reveal predictive parts of
the image and hide the un-predictive parts.
</pre>

<code>MASK_BLACK = 4;</code>
java-vertexai/proto-google-cloud-vertexai-v1/src/main/java/com/google/cloud/vertexai/api/ExplanationMetadata.java