def swap_anchor(new_anchor)
      new_anchor.drawing.anchors.delete(new_anchor)
      @anchor.drawing.anchors[@anchor.drawing.anchors.index(@anchor)] = new_anchor
      new_anchor.instance_variable_set "@object", @anchor.object
      @anchor = new_anchor
    end
def swap_anchor(new_anchor)
      new_anchor.drawing.anchors.delete(new_anchor)
      @anchor.drawing.anchors[@anchor.drawing.anchors.index(@anchor)] = new_anchor
      new_anchor.instance_variable_set "@object", @anchor.object
      @anchor = new_anchor
    end
refactoring of swapping code, law of demeter be damned!