cross: {
  start: ""
  end: ""
  start.1 <-> end.1: 1 {
    style.stroke-width: 1
    source-arrowhead.shape: cross
    target-arrowhead.shape: cross
  }
  start.2 <-> end.2: 2 {
    style.stroke-width: 2
    source-arrowhead.shape: cross
    target-arrowhead.shape: cross
  }
  start.4 <-> end.4: 4 {
    style.stroke-width: 4
    source-arrowhead.shape: cross
    target-arrowhead.shape: cross
  }
  start.8 <-> end.8: 8 {
    style.stroke-width: 8
    source-arrowhead.shape: cross
    target-arrowhead.shape: cross
  }
  start.15 <-> end.15: 15 {
    style.stroke-width: 15
    source-arrowhead.shape: cross
    target-arrowhead.shape: cross
  }
}