def METHOD_NAME(self):
    self.event.settings.primary_color = "#34c34c"
    regenerate_css.apply(args=(self.event.pk,))
    self.event.settings.flush()
    fname = self.event.settings.presale_css_file
    self.event.settings.primary_color = "#ff00ff"
    regenerate_css.apply(args=(self.event.pk,))
    self.event.settings.flush()
    assert self.event.settings.presale_css_file != fname