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) {
        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>(
                getAssetGcsSource(), getParentForChildren(), isClean());
        assetGcsSource_ = null;
      }
      return assetGcsSourceBuilder_;
    }
<pre>
Output only. The original cloud storage source uri that is associated with
this asset.
</pre>

<code>
.google.cloud.visionai.v1.AssetSource.AssetGcsSource asset_gcs_source = 4 [(.google.api.field_behavior) = OUTPUT_ONLY];
</code>
java-visionai/proto-google-cloud-visionai-v1/src/main/java/com/google/cloud/visionai/v1/Asset.java