This is the multi-stage graph representation in python

graph = [ 
    (0, {}), 
    (1, {3: 2, 4: 9}), 
    (1, {3: 6, 4: 3}), 
    (2, {4: 1}), 
    (2, {5: 4}), 
    (3, {5: 7}), 
    (3, {6: 2}), 
    (4, {5: 1, 6: 5}), 
    (4, {6: 6}), 
    (5, {}), 
    (5, {}), 
    (6, {}), 
    (6, {}), 
] 

It is from the geeks for geeks article. Can someone please explain this?

https://www.geeksforgeeks.org/multistage-graph-shortest-path/

I am trying to draw this graph but it is not making sense. especially for node 3 and 4 how can two nodes of the same stage be connected