def updateScenegraph(self, dagNodes):
        if dagNodes and len(dagNodes) == 1:
            liveSceneGraph = self.dag.buildSceneGraph(dagNodes[0])
            self.sceneGraphWidget.rebuild(liveSceneGraph, dagNodes[0])
        else:
            self.sceneGraphWidget.rebuild(None, None)
Initializes the shell application by registering some signals
dataset/ETHPy150Open andrew-gardner/dependsworkflow/depends/depends_main_window.py/MainWindow.updateScenegraph--crossover with--dataset/ETHPy150Open StorjOld/downstream-farmer/downstream_farmer/utils.py/ShellApplication.__init__