@Override
  public void revokePrivilegeFromUser(String username, PrivilegeUnion union) throws AuthException {
    checkAdmin(username, "Invalid operation, administrator must have all privileges");
    userManager.revokePrivilegeFromEntity(username, union);
  }
Checks if a user has admin privileges
iotdb-core/node-commons/src/main/java/org/apache/iotdb/commons/auth/authorizer/BasicAuthorizer.java