docs: private void updateMethodMap(Map<RequestMethod, List<Integer>> methodMap, Integer roleId, String methodMask) {
          for (int i = 0; i < RoleResourceConstant.METHOD_NUM; ++i) {
              if (methodMask.charAt(i) == RoleResourceConstant.METHOD_IS_ACCESSIBLE) {
                  RequestMethod curMethod = RoleResourceConstant.IND_METHOD_MAP.get(i);
  
                  // update List<roleId>
                  List<Integer> roleIdList = methodMap.get(curMethod);
                  if (roleIdList == null) {
                      roleIdList = new ArrayList<Integer>();
                      methodMap.put(curMethod, roleIdList);
                  }
                  roleIdList.add(roleId);
              }
          }
      }