事件的添加，触发，删除

时间的侦听

function Events(){
}
Events.prototype.on=function(action,func){
    this[action] = func;
}
Events.prototype.trigger= function (action) {
    if(this.hasOwnProperty(action)){
        this[action]();
    }
}
Events.prototype.off = function(action){
    if(this.hasOwnProperty(action)){
        delete this[action];
    }
}


var object = new Events();
//
object.on('sleep',function(){
    console.log('sleep');
})
object.trigger('sleep');

object.off('sleep');

object.trigger('sleep');