Handle compound medial tires in cut labelling

papers/medial_tire_decompositions_of_plane_triangulations/lib/draw_random_medial_tire_decompositions.py

@@ -812,7 +812,10 @@ def run(args: argparse.Namespace):
     out_dir.mkdir(parents=True, exist_ok=True)
 
     if args.graph6:
-        graphs = [nx.from_graph6_bytes(args.graph6.encode())]
+        graph = nx.from_graph6_bytes(args.graph6.encode())
+        if nx.node_connectivity(graph) < 5:
+            raise ValueError("--graph6 graph must be 5-connected")
+        graphs = [graph]
         if args.source is None:
             raise ValueError("--source is required with --graph6")
         sources = [args.source]