docs: def ids_and_clean_visible_from_streamcorpus_chunk_path(corpus_path):
      '''converts a streamcorpus.Chunk file into the structure that is
      passed by the search engine to find_soft_selectors
  
      '''
      ch = clean_html(clean_html.default_config)
      cv = clean_visible(clean_visible.default_config)
      ids_and_clean_visible = []
      for si in streamcorpus.Chunk(path=corpus_path):
          if not si.body.clean_visible:
              ## attempt to make clean_visible
              if not si.body.raw:
                  logger.critical('no raw content, so skipping: %r', si.abs_url)
                  continue
              abs_url = si.abs_url
              si = ch(si, {})
              if not si:
                  logger.critical(
                      'failed to make clean_html, so skipping: %r', abs_url)
                  continue
              si = cv(si, {})
              if not si or not si.body.clean_visible:
                  logger.critical(
                      'failed to make clean_visible, so skipping: %r', abs_url)
                  continue
          rec = (si.stream_id, si.body.clean_visible.decode('utf8'), {})
          ids_and_clean_visible.append(rec)
      return ids_and_clean_visible