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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def init_widget(self):
 """ Initialize on the first call """

        #: Add a ActivityLifecycleListener to update the application state
        activity = self.widget
        activity.addActivityLifecycleListener(activity.getId())
        activity.onActivityLifecycleChanged.connect(
            self.on_activity_lifecycle_changed)

        #: Add BackPressedListener to trigger the event
        activity.addBackPressedListener(activity.getId())
        activity.onBackPressed.connect(self.on_back_pressed)

        #: Add ConfigurationChangedListener to trigger the event
        activity.addConfigurationChangedListener(activity.getId())
        activity.onConfigurationChanged.connect(self.on_configuration_changed)