Scenario: Add duplicate command.

src/View/Scenarios/GraphWidget.py

@@ -459,6 +459,19 @@ class GraphWidget(QGraphicsView):
         self.exec_with_waiting_window(fn, "delete_scenario")
         self.changeScenario.emit(self.sender())
 
+    def duplicate_scenario(self, item):
+        def fn():
+            self._close_other_window()
+            # self._study.save()
+            self._undo.push(
+                DuplicateScenariosCommand(
+                    self._study,
+                )
+            )
+
+        self.exec_with_waiting_window(fn, "duplicate_scenario")
+        self.changeScenario.emit(self.sender())
+
     def _close_other_window(self):
         self.parent\
             .parent\