Expands a graph by replacing a node with a triangle. This operation preserves 3-regularity and planarity. G.add_edge(neighbors[0], v1) G.add_edge(neighbors[1], v2) G.add_edge(neighbors[2], v3) ...

# face = [(7, 6), (6, 1), (1, 2), (2, 4), (4, 3), (3, 2), (2, 1), (1, 5), (5, 7)] # In this example (1, 2) is the edge that make to graph 1-edge-connected ...