graph
[
  directed 1
  node [id 0 weight 0.0]
  node [id 1 weight 0.0]
  node [id 2 weight 2.0]

  node [id 3 weight 1.0]

  node [id 4 weight 2.0]
  node [id 5 weight 2.0]
  node [id 6 weight 2.0]

  edge [source 0 target 3]
  edge [source 1 target 3]
  edge [source 2 target 3]

  edge [source 3 target 4]
  edge [source 3 target 5]
  edge [source 3 target 6]
]