public string setForumMaxAdmins(string forumName, int maxAdmins, string requestingUser)
        {
            List <string> input = new List <string>()
            {
                forumName
            };

            if (Constants.isValidInput(input))
            {
                lock (o)
                {
                    if (_um.getUserPermissionsForForum(forumName, requestingUser) != permission.SUPER_ADMIN && _um.getUserPermissionsForForum(forumName, requestingUser) != permission.ADMIN)
                    {
                        return("Unauthorized user");
                    }
                    int numOfAdmins = _um.getNumOfAdmins(forumName);
                    if (numOfAdmins > maxAdmins)
                    {
                        return(Constants.ILLEGAL_ACTION);
                    }
                    if (!_fm.setForumMaxAdmins(forumName, maxAdmins))
                    {
                        return(Constants.forumDoesntExist(forumName));
                    }
                    return(Constants.SUCCESS);
                }
            }
            return(Constants.INVALID_INPUT);
        }