lib/tethys.js
function(events, fn){

        events = events.split(/\s*\,\s*/);

        return this.each(function(el){

            fn = fn.bind(el);

            events.forEach(function(event){
                el.addEventListener(event, fn);
            });
        });
    }
function(events, fn){

        events = events.split(/\s*\,\s*/);

        return this.each(function(el){

            fn = fn.bind(el);

            events.forEach(function(event){
                el.addEventListener(event, fn);
            });
        });
    }
绑定事件