Link Label Dragging with a tether line to the label

This sample is a modification of the Link Label Dragging Tool sample, adding a dashed line between the main "ICON" and the label.

Diagram Model saved in JSON format:

{ "class": "go.GraphLinksModel",
  "nodeKeyProperty": "id",
  "nodeDataArray": [
    { "id": 0, "loc": "120 120", "text": "Initial" },
    { "id": 1, "loc": "330 120", "text": "First down" },
    { "id": 2, "loc": "226 376", "text": "First up" },
    { "id": 3, "loc": "60 276", "text": "Second down" },
    { "id": 4, "loc": "226 226", "text": "Wait" }
  ],
  "linkDataArray": [
    { "from": 0, "to": 0, "text": "up or timer", "curviness": -20 },
    { "from": 0, "to": 1, "text": "down", "curviness": 20 },
    { "from": 1, "to": 0, "text": "up (moved)\nPOST", "curviness": 20 },
    { "from": 1, "to": 1, "text": "down", "curviness": -20 },
    { "from": 1, "to": 2, "text": "up (no move)" },
    { "from": 1, "to": 4, "text": "timer" },
    { "from": 2, "to": 0, "text": "timer\nPOST" },
    { "from": 2, "to": 3, "text": "down" },
    { "from": 3, "to": 0, "text": "up\nPOST\n(dblclick\nif no move)" },
    { "from": 3, "to": 3, "text": "down or timer", "curviness": 20 },
    { "from": 4, "to": 0, "text": "up\nPOST" },
    { "from": 4, "to": 4, "text": "down" }
  ]
}