@java.lang.Override
    public boolean hasGcsSource() {
      return sourceCase_ == 3;
    }
<pre>
Google Cloud Storage file source.
</pre>

<code>.google.cloud.translation.v3.GcsInputSource gcs_source = 3;</code>

@return Whether the gcsSource field is set.
java-translate/proto-google-cloud-translate-v3/src/main/java/com/google/cloud/translate/v3/DatasetInputConfig.java