protected final void requirePermission(String request, Permission.Action perm)
    throws IOException {
    if (accessChecker != null) {
      accessChecker.requirePermission(RpcServer.getRequestUser().orElse(null), request, null, perm);
    }
  }
Base class for Master and RegionServer RpcServices.
hbase-server/src/main/java/org/apache/hadoop/hbase/HBaseRpcServicesBase.java