public Map<String, Long> getCallQueueCountsSummary() {
    return queues.stream().flatMap(Collection::stream).map(RpcExecutor::getMethodName)
      .collect(Collectors.groupingBy(Function.identity(), Collectors.counting()));
  }
Return the {@link RpcCall#getSize()} from {@code callRunner} or 0L.
hbase-server/src/main/java/org/apache/hadoop/hbase/ipc/RpcExecutor.java