fixup! Format Python code with psf/black push

Author: github-actions

graphs/breadth_first_search_shortest_path.py

@@ -67,6 +67,7 @@ def shortest_path(self, target_vertex):
 
 if __name__ == "__main__":
     import doctest
+
     doctest.testmod()
     g = Graph(graph, "G")
     g.breath_first_search()