function(fn) {
		var index = 0,
			model = this;

		while (model != null) {
			if (fn.call(this, model, index++)) return model;
			model = model.parent;
		}
	}
function(fn) {
		var index = 0,
			model = this;

		while (model != null) {
			if (fn.call(this, model, index++)) return model;
			model = model.parent;
		}
	}
function ( fn ) { var index = 0 , model = this ; while ( model != null ) { if ( fn . call ( this , model , index ++ ) ) return model ; model = model . parent ; } }
returns the first model which passes the function
returns the first model which passes the function