gistfile1.js

Class('MyClass')({
    prototype : {
        init : function (options){
            this.myProperty = 'value';
            this.myMethod();
        },
        myMethod : function(){
            
            var myArbitraryNamedClosue = this;

            console.log('This is my: ', this.myProperty); // this is my: value

            ['a', 'b', 'c'].forEach(function(){
                //without a closure
                console.log('This is my: ', this.myProperty); // this is my: undefined

                //with closue
                console.log('This is my: ', myArbitraryNamedClosue.myProperty); // this is my: velue

            });

        }
    }
});