Add incoming_links to abstract Node for mock_assignment

Author: s-hiitola

Scripts/assignment/emme_bindings/mock_project.py

@@ -712,6 +712,9 @@ def id(self):
     def outgoing_segments(self, include_hidden=False):
         return (s for s in self.network.transit_segments(include_hidden)
             if s.i_node is self)
+    
+    def incoming_links(self):
+        return (l for l in self.network.links() if l.j_node is self)
 
 class Link(NetworkObject):
     def __init__(self,