pep8: Change to respect pep8 code style.

src/Model/Network/Graph.py

@@ -213,7 +213,7 @@ class Graph(object):
     def is_enable_edge(self, edge):
         return edge._enable
 
-    #def get_edge_id(self, reach):
+    # def get_edge_id(self, reach):
     #    for i, e in enumerate(self.enable_edges):
     #        if e.id == reach.id:
     #            return i