docs: def search_texts(args, parser):
      """Searches texts for presence of n-grams."""
      store = utils.get_data_store(args)
      corpus = utils.get_corpus(args)
      catalogue = utils.get_catalogue(args)
      store.validate(corpus, catalogue)
      ngrams = []
      for ngram_file in args.ngrams:
          ngrams.extend(utils.get_ngrams(ngram_file))
      store.search(catalogue, ngrams, sys.stdout)