anchor.diff:    Point<int> _cursor1;
     Point<int> _cursor2;
     Playfield playfield;
  +
     Cursor(Point<int> cursor1, Point<int> cursor2, Playfield field)
     {
       this._cursor1 = cursor1;
  
positive.code: import "dart:math";
  import "Playfield.dart";
  
  enum Direction
  {
  
negative.code:   }
    void swap()
    {
      Block fCursor01;
      Block fCursor02;
      // switch Positions inside the Blocks
      fCursor01 = playfield.getBlockFromField(_cursor1);
      fCursor01.setPos(_cursor2);
      fCursor02 = playfield.getBlockFromField(_cursor2);
      fCursor02.setPos(_cursor1);
      // set into the Field from Cursor 01
      playfield.setBlockIntoField(fCursor01);
      // set into the Field from Cursor 02
      playfield.setBlockIntoField(fCursor02);
    }
  }