'Generate the CSS font family
A generic font can be found in two ways. In a <style:font-face>
element or as a font-family-generic attribute in text-properties.'

def c_fn(self, ruleset, sdict, rule, fontstyle):

    generic = ruleset.get((STYLENS, 'font-family-generic'))
    if (generic is not None):
        self.save_font(fontstyle, fontstyle, generic)
    (family, htmlgeneric) = self.fontdict.get(fontstyle, (fontstyle, 'serif'))
    sdict['font-family'] = ('%s,    %s' % (family, htmlgeneric))
