docs: def flattenPorts(root: LNode):
      """
      Flatten ports to simplify layout generation
  
      :attention: children property is destroyed, parent property stays same
      """
      for u in root.children:
          u.west = _flattenPortsSide(u.west)
          u.east = _flattenPortsSide(u.east)
          u.north = _flattenPortsSide(u.north)
          u.south = _flattenPortsSide(u.south)