code: public boolean hasPermissionForUser(String user, List<String> permission) {
          return hasPermissionForUser(user, permission.toArray(new String[0]));
      }
docs: hasPermissionForUser determines whether a user has a permission.
  
  @param user the user.
  @param permission the permission, usually be (obj, act). It is actually the rule without the subject.
  @return whether the user has the permission.