'Set the font size.  May be either a size string, relative to
the default font size, or an absolute font size in points.
ACCEPTS: [size in points | \'xx-small\' | \'x-small\' | \'small\' |
\'medium\' | \'large\' | \'x-large\' | \'xx-large\' ]'

def set_size(self, fontsize):

    self._fontproperties.set_size(fontsize)
    self.stale = True
