@java.lang.Override
    public com.google.cloud.translate.v3.GcsSource getGcsSource() {
      if (gcsSourceBuilder_ == null) {
        if (sourceCase_ == 2) {
          return (com.google.cloud.translate.v3.GcsSource) source_;
        }
        return com.google.cloud.translate.v3.GcsSource.getDefaultInstance();
      } else {
        if (sourceCase_ == 2) {
          return gcsSourceBuilder_.getMessage();
        }
        return com.google.cloud.translate.v3.GcsSource.getDefaultInstance();
      }
    }
<pre>
Google Cloud Storage location. This must be a single file.
For example: gs://example_bucket/example_file.pdf
</pre>

<code>.google.cloud.translation.v3.GcsSource gcs_source = 2;</code>

@return The gcsSource.
java-translate/proto-google-cloud-translate-v3/src/main/java/com/google/cloud/translate/v3/DocumentInputConfig.java