public Builder clearGcsSource() {
      if (gcsSourceBuilder_ == null) {
        if (sourceCase_ == 1) {
          sourceCase_ = 0;
          source_ = null;
          onChanged();
        }
      } else {
        if (sourceCase_ == 1) {
          sourceCase_ = 0;
          source_ = null;
        }
        gcsSourceBuilder_.clear();
      }
      return this;
    }
<pre>
The Google Cloud Storage location for a csv file which preserves a list
of ImportProductSetRequests in each line.
</pre>

<code>.google.cloud.vision.v1.ImportProductSetsGcsSource gcs_source = 1;</code>
java-vision/proto-google-cloud-vision-v1/src/main/java/com/google/cloud/vision/v1/ImportProductSetsInputConfig.java