https://docs.oracle.com/middleware/1213/wls/WLAPI/weblogic/xml/stream/events/ElementEvent.html
ElementEvent (Java API Reference for Oracle WebLogic Server)
java apioracle weblogicreferenceserver
https://beam.apache.org/releases/javadoc/2.22.0/org/apache/beam/sdk/testing/TestStream.ElementEvent.html
TestStream.ElementEvent (Apache Beam 2.22.0)
apache beamteststream