<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def contextMenuEvent(self, event):
 """ Shows the context menu at the cursor position We need to take the event-based approach because ArgosPgPlotItem does derives from QGraphicsWidget, and not from QWidget, and therefore doesn't have the customContextMenuRequested signal. """

        contextMenu = QtWidgets.QMenu()
        for action in self.actions():
            contextMenu.addAction(action)
        contextMenu.exec_(event.screenPos())