public virtual bool CanExecute(object parameter)        {            bool hasEnabledCommandsThatShouldBeExecuted = false;            ICommand[] commandList;            lock (this.registeredCommands)            {                commandList = this.registeredCommands.ToArray();            }            foreach (ICommand command in commandList)            {                if (this.ShouldExecute(command))                {                    if (!command.CanExecute(parameter))                    {                        return false;                    }                    hasEnabledCommandsThatShouldBeExecuted = true;                }            }            return hasEnabledCommandsThatShouldBeExecuted;        }