anchor.diff:        _draggable.style
             ..left = "0"
             ..right = "0"
  -          ..top = "-3px"
  -          ..height = "7px";
  +          ..top = "-${draggableStart}px"
  +          ..height = "${draggableSize}px";
       } else {
         style
             ..height = "auto"
  
positive.code: 
  @CustomTag('spark-splitter')
  class SparkSplitter extends SparkWidget {
    /// Possible values are "left", "right", "up" and "down".
    /// The direction specifies:
    /// 1) whether the split is horizontal or vertical;
  
negative.code:       _draggable.style
            ..bottom = "0"
            ..top = "0"
            ..left = "-${draggableStart}px"
            ..width = "${draggableSize}px";
      }
    }
  
  