Failed to run gateway = net.attrs["IPAM"]["Config"][0]["Subnet"] TypeError: 'NoneType' object is not subscriptable

[d-hieu-00]

I got error when try run this Same as when use the docker image docker run --rm -v /var/run/docker.sock:/var/run/docker.sock leoverto/docker-network-graph

sudo python3 -m pipenv --python=/usr/bin/python3 run python docker-net-graph.py -o output.svg
Traceback (most recent call last):
  File "/home/era/docker-network-graph/docker-net-graph.py", line 211, in <module>
    generate_graph(args.verbose, args.out)
  File "/home/era/docker-network-graph/docker-net-graph.py", line 173, in generate_graph
    networks = get_networks(docker_client, verbose)
  File "/home/era/docker-network-graph/docker-net-graph.py", line 66, in get_networks
    gateway = net.attrs["IPAM"]["Config"][0]["Subnet"]
TypeError: 'NoneType' object is not subscriptable