code: function(methodName) {
      var args, ret = [];
      if (arguments.length>1) args = a_slice.call(arguments, 1);
  
      this.forEach(function(x, idx) {
        var method = x && x[methodName];
        if ('function' === typeof method) {
          ret[idx] = args ? method.apply(x, args) : method.call(x);
        }
      }, this);
  
      return ret;
    }
docs: Invokes the named method on every object in the receiver that
  implements it.  This method corresponds to the implementation in
  Prototype 1.6.
  
  @param {String} methodName the name of the method
  @param {Object...} args optional arguments to pass as well.
  @returns {Array} return values from calling invoke.