docs: @Override
      public List<String> getUsers(String name) {
          if (!hasRole(name)) {
              throw new Error("error: name does not exist");
          }
  
          List<String> names = new ArrayList<>();
          for (Role role : allRoles.values()) {
              if (role.hasDirectRole(name)) {
                  names.add(role.name);
              }
          }
          return names;
      }