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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 button_state(self):
 		"""The button state that triggered this event. 		For pointer events that are not of type 		:attr:`~libinput.constant.EventType.POINTER_BUTTON`, this property 		raises :exc:`AttributeError`. 		Returns: 			~libinput.constant.ButtonState: The button state triggering this 			event. 		Raises: 			AttributeError 		"""


		if self.type != EventType.POINTER_BUTTON:
			raise AttributeError(_wrong_prop.format(self.type))
		return self._libinput.libinput_event_pointer_get_button_state(
			self._handle)