How to save and add width and speed from json.graph file into edges(links)

    {
      "directed": false,
      "multigraph": false,
      "graph": {},
      "nodes": [
        {
          "pos": [
            40.7842494,
            -73.9470901
          ],
          "id": 42443054
        }
  ],
  "links": [
    {
        {
          "attr": {
            "speed": "20 mph",
            "width": "2'",
            "label": "edge 11 secondary",
            "isPrimary": false
          },
          "source": 7067139595,
          "target": 7067139597
        }
      ]
    }

Here i have graph.json file.
what i did is that I imported and saved the nodes into my graph jsnx, but I am having very tough time in importing and saving the source, target, speed and width from the attr into my edges(links).

Please if someone can help me I would really really appreciate, due to a lot of information online I am really so lost.

Thanks in advance!