@java.lang.Override
  public boolean hasGcsSource() {
    return sourceCase_ == 2;
  }
<pre>
Google Cloud Storage location. This must be a single file.
For example: gs://example_bucket/example_file.pdf
</pre>

<code>.google.cloud.translation.v3beta1.GcsSource gcs_source = 2;</code>

@return Whether the gcsSource field is set.
java-translate/proto-google-cloud-translate-v3beta1/src/main/java/com/google/cloud/translate/v3beta1/DocumentInputConfig.java