public Builder clearGcsInputSource() {
      if (gcsInputSourceBuilder_ == null) {
        if (sourceCase_ == 3) {
          sourceCase_ = 0;
          source_ = null;
          onChanged();
        }
      } else {
        if (sourceCase_ == 3) {
          sourceCase_ = 0;
          source_ = null;
        }
        gcsInputSourceBuilder_.clear();
      }
      return this;
    }
<pre>
Google Cloud Storage file source.
</pre>

<code>.google.cloud.translation.v3.GcsInputSource gcs_input_source = 3;</code>
java-translate/proto-google-cloud-translate-v3/src/main/java/com/google/cloud/translate/v3/ImportAdaptiveMtFileRequest.java