function before(n, func) {
      var result;
      if (!isFunction(func)) {
        if (isFunction(n)) {
          var temp = n;
          n = func;
          func = temp;
        } else {
          throw new TypeError(FUNC_ERROR_TEXT);
        }
      }
      return function() {
        if (--n > 0) {
          result = func.apply(this, arguments);
        } else {
          func = null;
        }
        return result;
      };
    }
Creates a function that invokes `func`, with the `this` binding and arguments
of the created function, while it is called less than `n` times. Subsequent
calls to the created function return the result of the last `func` invocation.

@static
@memberOf _
@category Function
@param {number} n The number of calls at which `func` is no longer invoked.
@param {Function} func The function to restrict.
@returns {Function} Returns the new restricted function.
@example

jQuery('#add').on('click', _.before(5, addContactToList));
// => allows adding up to 4 contacts to the list