'Temporarily sets the current theme to themename, apply specified
settings and then restore the previous theme.
Each key in settings is a style and each value may contain the
keys \'configure\', \'map\', \'layout\' and \'element create\' and they
are expected to have the same format as specified by the methods
configure, map, layout and element_create respectively.'

def theme_settings(self, themename, settings):

    script = _script_from_settings(settings)
    self.tk.call(self._name, 'theme', 'settings', themename, script)
