code: function(fn) {
    var code = fn.toString();
    var match = code.match(/^(?:(?:function)?[\s]*\(([^)]*)\)|([^\=\(]+))/);
    var args = (match[1] || match[2]);
    if (typeof args === 'undefined') {
      return [];
    }
    return args.split(',').map(function(item) {
      return item.trim();
    }).filter(function(item) {
      return item;
    });
  }
docs: List function arguments.