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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 _on_wheel_event(self, event):
 """ Increments or decrements editor fonts settings on mouse wheel event if ctrl modifier is on. :param event: wheel event :type event: QWheelEvent """

        try:
            delta = event.angleDelta().y()
        except AttributeError:
            # PyQt4/PySide
            delta = event.delta()
        if int(event.modifiers()) & QtCore.Qt.ControlModifier > 0:
            if delta < self.prev_delta:
                self.editor.zoom_out()
                event.accept()
            else:
                self.editor.zoom_in()
                event.accept()