private static String getMethodName(final CallRunner callRunner) {
    return Optional.ofNullable(callRunner).map(CallRunner::getRpcCall).map(RpcCall::getMethod)
      .map(Descriptors.MethodDescriptor::getName).orElse("Unknown");
  }
Return the {@link Descriptors.MethodDescriptor#getName()} from {@code callRunner} or "Unknown".
hbase-server/src/main/java/org/apache/hadoop/hbase/ipc/RpcExecutor.java