public ClientUser AddToChatList(ClientUser forUser, string contactUserName) { ClientUser contactToAdd = _storageHandler.GetUserByUserName(contactUserName); if (contactToAdd == null) { throw new FaultException($"Account with user name '{contactUserName}' is not registered. Please try again."); } try { _storageHandler.AddChatContact(forUser, contactToAdd); } catch (Exception) { throw new FaultException("Unknown error. Please try again."); } return(contactToAdd); }