JavaScript Run Once Function

/**
 * Execute a function only once per instance.
 *
 * @param {...*} arguments
 *
 * @return {*}
 *   The return value of the function's first execution.
 */
Function.prototype.once = function() {
  var _self = this,
    args  = arguments;

  return function() {
    if (!this.hasRun) {
      this.result = _self.apply(_self, args);
      this.hasRun = true;
    }

    return this.result;
  }();
};

// Usage
// var foo = function() { console.log('foo!'); };
// foo.once(); // Prints 'foo!'
// foo.once(); // Doesn't print anything.