private com.google.protobuf.SingleFieldBuilderV3<
            com.google.cloud.vision.v1p3beta1.ImportProductSetsGcsSource,
            com.google.cloud.vision.v1p3beta1.ImportProductSetsGcsSource.Builder,
            com.google.cloud.vision.v1p3beta1.ImportProductSetsGcsSourceOrBuilder>
        getGcsSourceFieldBuilder() {
      if (gcsSourceBuilder_ == null) {
        if (!(sourceCase_ == 1)) {
          source_ =
              com.google.cloud.vision.v1p3beta1.ImportProductSetsGcsSource.getDefaultInstance();
        }
        gcsSourceBuilder_ =
            new com.google.protobuf.SingleFieldBuilderV3<
                com.google.cloud.vision.v1p3beta1.ImportProductSetsGcsSource,
                com.google.cloud.vision.v1p3beta1.ImportProductSetsGcsSource.Builder,
                com.google.cloud.vision.v1p3beta1.ImportProductSetsGcsSourceOrBuilder>(
                (com.google.cloud.vision.v1p3beta1.ImportProductSetsGcsSource) source_,
                getParentForChildren(),
                isClean());
        source_ = null;
      }
      sourceCase_ = 1;
      onChanged();
      return gcsSourceBuilder_;
    }
<pre>
The Google Cloud Storage location for a csv file which preserves a list
of ImportProductSetRequests in each line.
</pre>

<code>.google.cloud.vision.v1p3beta1.ImportProductSetsGcsSource gcs_source = 1;</code>
java-vision/proto-google-cloud-vision-v1p3beta1/src/main/java/com/google/cloud/vision/v1p3beta1/ImportProductSetsInputConfig.java