define(function () {

  // In Firefox, `Function.prototype.call` is faster than
  // `Function.prototype.apply`. In the optimized variant of
  // `bindCb` below, we exploit the fact that no Underscore
  // function passes more than four arguments to a callback.
  // **NOT general enough for use outside of Underscore.**
  function bindCb4(func, context) {
    if (context === void 0) return func;
    return function(a1, a2, a3, a4) {
      return func.call(context, a1, a2, a3, a4);
    };
  }

  return bindCb4;

});