docs: @Override
      public List<String> getGroupsForUser(String userSecurityName) throws EntryNotFoundException, RegistryException {
          if (userSecurityName == null) {
              throw new IllegalArgumentException("userSecurityName is null");
          }
          if (userSecurityName.isEmpty()) {
              throw new IllegalArgumentException("uniqueGroupId is an empty String");
          }
          if (user.equals(userSecurityName)) {
              return new ArrayList<String>();
          } else {
              throw new EntryNotFoundException(REALM_NAME + " does not support groups");
          }
      }