def button(self):
		"""The button that triggered this event.

		For events that are not of type
		:attr:`~libinput.constant.EventType.TABLET_TOOL_BUTTON`, this property
		raises :exc:`AttributeError`.

		Returns:
			int: The button triggering this event.
		"""

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