code: function polygonReverse(polygon){
      var tmp = [];
      var N = polygon.length;
      for(var i=0; i!==N; i++){
          tmp.push(polygon.pop());
      }
      for(var i=0; i!==N; i++){
  		polygon[i] = tmp[i];
      }
  }
docs: Reverse the vertices in the polygon
  @method reverse