'Sets the labels of axis ``axis_id`` to ``labels``. This is used for axes displaying a discrete data type.
:param labels: The ID of the axis to change
:type labels: int
:param labels: The list of labels to be displayed along the axis
:type labels: A list of strings
.. note:: This changes the axis scale and removes any previous scale set with :meth:`set_axis_scale`.'

def set_axis_labels(self, axis_id, labels, values=None):

    if (axis_id in self._bounds_cache):
        del self._bounds_cache[axis_id]
    self._transform_cache = {}
    self.axes[axis_id].set_labels(labels, values)
