code: function addFlexibleLayout() {
      var modifier = new Modifier({
          size: [200, 200],
          transform: Transform.translate(200, 0)
      });
  
      var layout = new FlexibleLayout({
          direction: Utility.Direction.X,
          ratios: [true, 1, 2, 3, true]
      });
  
      function getItem() {
          return new Surface({
              properties: {
                  backgroundColor: getRandomColor()
              }
          });
      }
  
      var items = [
          new Surface({
              size: [20, undefined],
              properties: {
                  backgroundColor: getRandomColor()
              }
          }),
          getItem(),
          getItem(),
          getItem(),
          new Surface({
              size: [10, undefined],
              properties: {
                  backgroundColor: getRandomColor()
              }
          })
      ];
  
      layout.sequenceFrom(items);
      ctx.add(modifier).add(layout);
  }
docs: /*
  FlexibleLayout