Underscore.js 1.7の使い方 Functions編 before

var r = document.getElementById("r");
var i = 0;
var beforeFunc = _.before(3, render);
function render () {
  i++;
  r.innerHTML += i + '回目
';
}
beforeFunc();
r.innerHTML += '
';
beforeFunc();
r.innerHTML += '
';
// 3つ目のbeforeFunc()から処理が実行されない
beforeFunc();
r.innerHTML += '
';
beforeFunc();
r.innerHTML += '
';
beforeFunc();