private InternalGatewaySender getInternalGatewaySender() {
    InternalGatewaySender gatewaySender = getInternalAsyncEventQueue().getSender();
    assertThat(gatewaySender).isNotNull();
    return gatewaySender;
  }
Regression test for TRAC #50366: NullPointerException with AsyncEventQueue#size() when number
of dispatchers is more than 1
geode-core/src/distributedTest/java/org/apache/geode/internal/cache/wan/asyncqueue/ConcurrentAsyncEventListenerDistributedTest.java