     wall.attr({
        size: [10, 740],
        pos: [940, 250],
        bgcolor: '#CFC441',
      });
      fglayer.append(wall);

      function randomBirds(i) {
        const pos = [100, 350 + 60 * i];
        const duration = Math.round(200 + 300 * Math.random());

        const g = new Group();
        g.attr({
          anchor: [0.5, 0.5],
          pos,
          zIndex: 200,
        });

        const s = new Sprite('huanhuan.png');
        s.attr({scale: 0.4});

        g.appendChild(s);

       