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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 size(self):
 		"""The physical size of a device in mm, where meaningful. 		This property is only valid on devices with the required data, i.e. 		tablets, touchpads and touchscreens. For other devices this property 		raises :exc:`AssertionError`. 		Returns: 			(float, float):
 (Width, Height) in mm. 		Raises: 			AssertionError 		"""


		width = c_double(0)
		height = c_double(0)
		rc = self._libinput.libinput_device_get_size(
			self._handle, byref(width), byref(height))
		assert rc == 0, 'This device does not provide size information'
		return width.value, height.value