This PR fixes a jdk9 incompatibility regarding generics. The method compilation fails on java 9 since the CONNECTOR_SINK_PARTITIONER_VALUE_CUSTOM branch returns an Optional<Class<? extends FlinkKafkaPartitioner>>, but the method requires a Optional<FlinkKafkaPartitioner<Row>>.
The compiler obviously cannot infer that the instantiated partitioner is always a `FlinkKafkaPartitioner<Row>` (since it technically could work on any type), so we have to help a bit. [ Full content available at: https://github.com/apache/flink/pull/6653 ] This message was relayed via gitbox.apache.org for [email protected]
