//private CommandBindingCollection _commandBindings;
        //private CrewViewModel _owner;

        public CrewSkillViewModel(CommandBindingCollection commandBindings, CrewSkill skill, CrewViewModel owner)
            : base(skill, owner)
        {
            this.ToggleCommand = Command.FromAction(commandBindings, this.ToggleLearnt);
        }
 static CrewViewModel()
 {
     SFirstSkillExperience = CrewViewModel.GetLevelUpExperience(100);
 }