Network: Add add node command.

src/Model/Network/Graph.py

@@ -81,22 +81,32 @@ class Graph(object):
 
         return edge[0]
 
-    def _add_node(self, node):
-        self._nodes.append(node)
-        self._nodes_ids += 1
-
-        self._status.modified()
-        return node
-
-    def add_node(self, x:float = 0.0, y:float = 0.0):
+    def _create_node(self, x:float, y:float):
         node = self._node_ctor(
             self._nodes_ids,
             f"Node {self._nodes_ids}",
             x = x, y = y,
             status = self._status
         )
+        self._nodes_ids += 1
+        return node
+
+    def _add_node(self, node):
+        self._nodes.append(node)
+        self._status.modified()
+        return node
+
+    def add_node(self, x:float = 0.0, y:float = 0.0):
+        node = self._create_node(x, y)
         return self._add_node(node)
 
+    def insert_node(self, node):
+        self._add_node(node)
+
+    def create_node(self, x:float = 0.0, y:float = 0.0):
+        node = self._create_node(x, y)
+        return node
+
     def _add_edge(self, edge):
         # This edge already exists ?
         if any(filter(lambda e: (e.node1 == edge.node1 and