private com.google.protobuf.SingleFieldBuilderV3<
            com.google.cloud.visionai.v1.AssetSource.AssetGcsSource,
            com.google.cloud.visionai.v1.AssetSource.AssetGcsSource.Builder,
            com.google.cloud.visionai.v1.AssetSource.AssetGcsSourceOrBuilder>
        getAssetGcsSourceFieldBuilder() {
      if (assetGcsSourceBuilder_ == null) {
        if (!(sourceFormCase_ == 1)) {
          sourceForm_ =
              com.google.cloud.visionai.v1.AssetSource.AssetGcsSource.getDefaultInstance();
        }
        assetGcsSourceBuilder_ =
            new com.google.protobuf.SingleFieldBuilderV3<
                com.google.cloud.visionai.v1.AssetSource.AssetGcsSource,
                com.google.cloud.visionai.v1.AssetSource.AssetGcsSource.Builder,
                com.google.cloud.visionai.v1.AssetSource.AssetGcsSourceOrBuilder>(
                (com.google.cloud.visionai.v1.AssetSource.AssetGcsSource) sourceForm_,
                getParentForChildren(),
                isClean());
        sourceForm_ = null;
      }
      sourceFormCase_ = 1;
      onChanged();
      return assetGcsSourceBuilder_;
    }
<pre>
The source of the asset is from Cloud Storage.
</pre>

<code>.google.cloud.visionai.v1.AssetSource.AssetGcsSource asset_gcs_source = 1;</code>
java-visionai/proto-google-cloud-visionai-v1/src/main/java/com/google/cloud/visionai/v1/AssetSource.java