class Acl {

  public static boolean addResourcePrefixGroup(Principal group, String identitySourceId) {
    checkNotNull(group);
    String groupName = group.getGroupResourceName();
    checkArgument(!Strings.isNullOrEmpty(groupName), "groupName can not be empty or null");
    if (groupName.startsWith(IDENTITY_SOURCES_PREFIX)) {
      return false;
    }
    group.setGroupResourceName(String.format(GROUP_NAME_FORMAT, identitySourceId, groupName));
    return true;
  }

  private  Acl(Builder builder);

}