Network: Fix edge delete whene there are multiple edge between two node.

src/Model/Network/Graph.py

@@ -142,26 +142,21 @@ class Graph(object):
     def insert_node(self, node):
         return self._add_node(node)
 
-    def remove_node(self, node_name: str):
-        self._nodes = list(
-            filter(
-                lambda n: n.name != node_name,
-                self._nodes
-            )
-        )
-        self._remove_associated_edge(node_name)
+    def remove_node(self, node):
+        self._nodes.remove(node)
+        self._remove_associated_edge(node)
         self._status.modified()
 
-    def _remove_associated_edge(self, node_name: str):
+    def _remove_associated_edge(self, node: str):
         edges = list(
             filter(
-                lambda e: (e.node1.name == node_name or
-                           e.node2.name == node_name),
+                lambda e: (e.node1 == node or
+                           e.node2 == node),
                 self._edges,
             )
         )
         for edge in edges:
-            self.remove_edge(edge.name)
+            self.remove_edge(edge)
 
     def create_node(self, x: float = 0.0, y: float = 0.0):
         node = self._create_node(x, y)
@@ -197,13 +192,8 @@ class Graph(object):
     def create_edge(self, n1: Node, n2: Node):
         return self._create_edge(n1, n2)
 
-    def remove_edge(self, edge_name: str):
-        self._edges = list(
-            filter(
-                lambda e: e.name != edge_name,
-                self._edges
-            )
-        )
+    def remove_edge(self, edge):
+        self._edges.remove(edge)
         self._status.modified()
 
     def is_upstream_node(self, node):