@Override
    public void preClose(ObserverContext<? extends RegionCoprocessorEnvironment> c,
      boolean abortRequested) throws IOException {
      // Wait so that the region can't close until we get the information we need from our test
      UTIL.waitFor(60_000, () -> THROWN_EXCEPTION.get() != null);
    }
Tests that the logic in ServerRpcConnection works such that if the server is aborted, it short
circuits any other logic. This means we no longer even attempt to enqueue the request onto the
call queue. We verify this by using a special call queue which we can trigger to always return
CallQueueTooBigException. If the logic works, despite forcing those exceptions, we should not
see them.
hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/TestRegionServerRejectDuringAbort.java