'Returns a dictionary mapping placeholder content and sekizai data.
Returns None if no cache is present.'

def _get_cached_placeholder_content(self, placeholder, site_id, language):

    site_cache = self._placeholders_content_cache.setdefault(site_id, {})
    language_cache = site_cache.setdefault(language, {})
    if (placeholder.pk not in language_cache):
        cached_value = get_placeholder_cache(placeholder, lang=language, site_id=site_id, request=self.request)
        if (cached_value != None):
            language_cache[placeholder.pk] = cached_value
    return language_cache.get(placeholder.pk)
