converts each :attr:`streamcorpus.StreamItem.body.clean_html` from
        `t_path` into a :class:`~dossier.fc.FeatureCollection` and saves it in
        a :class:`~dossier.store.Store` configured with the global `kvlayer`
        config.

def process(self, t_path, name_info, i_str):
        '''converts each :attr:`streamcorpus.StreamItem.body.clean_html` from
        `t_path` into a :class:`~dossier.fc.FeatureCollection` and saves it in
        a :class:`~dossier.store.Store` configured with the global `kvlayer`
        config.

        '''
        def cids_and_fcs():
            count = 0
            seen = set()
            for si in Chunk(t_path):
                clean_html = getattr(si.body, 'clean_html', '')
                if clean_html is None or len(clean_html.strip()) == 0:
                    logger.warn('dropping SI lacking clean_html: %r', si.abs_url)
                    continue
                if 'other_features' in si.other_content:
                    other_features = json.loads(si.other_content['other_features'].raw)
                else:
                    other_features = None
                fc = html_to_fc(
                    clean_html=si.body.clean_html.decode('utf-8'),
                    clean_visible=si.body.clean_visible.decode('utf-8'),
                    encoding='utf-8',
                    url=si.abs_url,
                    timestamp=si.stream_time.epoch_ticks,
                    other_features=other_features,
                )
                add_sip_to_fc(fc, self.tfidf)
                content_id = mk_content_id(str(fc.get(u'meta_url')))
                if content_id in seen:
                    logger.warn('dropping duplicate content_id=%r', content_id)
                else:
                    seen.add(content_id)
                    yield content_id, fc
                    count += 1
            logger.info('saved %d FCs from %d SIs', count, len(seen))
        self.store.put(cids_and_fcs())
        ## interface spec of streamcorpus_pipeline writers requires
        ## returning a list of locally generated paths.
        return []