https://beam.apache.org/releases/javadoc/2.22.0/org/apache/beam/sdk/transforms/join/RawUnionValue.html
RawUnionValue (Apache Beam 2.22.0)
apache beam
https://beam.apache.org/releases/javadoc/2.22.0/org/apache/beam/runners/gearpump/translators/utils/TranslatorUtils.RawUnionValue.html
TranslatorUtils.RawUnionValue (Apache Beam 2.22.0)
apache beam