@Override
        public boolean matches(AbstractRequest body) {
            if (body instanceof EndTxnRequest) {
                assertSame(requiredResult, ((EndTxnRequest) body).result());
                matched = true;
                return true;
            } else {
                return false;
            }
        }
Test the scenario that FetchResponse returns NOT_LEADER_OR_FOLLOWER, indicating change in leadership, along with
new leader info(defined in KIP-951).
clients/src/test/java/org/apache/kafka/clients/producer/internals/SenderTest.java