d', portFigure) // portFigure converter is defined below
              .bind('angle', 'angle')
          ),
      // hide a port when it is connected
      linkConnected: (node, link, port) => {
        if (link.category === '') port.visible = false;
      },
      linkDisconnected: (node, link, port) => {
        if (link.category === '') port.visible = true;
      }
    })
      // this creates the variable number of ports for this Spot Panel, based on the data
      .bind('itemArray', 'ports')
      // r