'Parameters
axes : :class:`~matplotlib.axes.Axes`
xref
yref'

def __init__(self, axes, xref=None, yref=None):

    self._axes = axes
    if (xref is None):
        self._xref = Size.AxesX(axes)
    else:
        self._xref = xref
    if (yref is None):
        self._yref = Size.AxesY(axes)
    else:
        self._yref = yref
    Divider.__init__(self, fig=axes.get_figure(), pos=None, horizontal=[self._xref], vertical=[self._yref], aspect=None, anchor=u'C')
