code: function makeArray( obj ) {
    var ary = [];
    if ( isArray( obj ) ) {
      // use object if already an array
      ary = obj;
    } else if ( typeof obj.length === 'number' ) {
      // convert nodeList to array
      for ( var i=0, len = obj.length; i < len; i++ ) {
        ary.push( obj[i] );
      }
    } else {
      // array of single index
      ary.push( obj );
    }
    return ary;
  }
docs: turn element or nodeList into an array