def kruskal(graph):
sortedE = []
for lst in graph:
for edge in lst:
sortedE.append(edge)
sortedE.sort(key=lambda e: e.weight) # sort by weight
item = GraphNode(6, weighted=True, directed=False) # 6 is # of numbers (?)
for edge in sortedE:
if not item.contains_cyle():
item.insert(edge.source, edge.dest, edge.weight)
return item
