code: def _check_import_source():
          
          path_rel = '~/cltk_data/greek/software/greek_software_tlgu/tlgu.h'
          path = os.path.expanduser(path_rel)
          if not os.path.isfile(path):
              try:
                  corpus_importer = CorpusImporter('greek')
                  corpus_importer.import_corpus('greek_software_tlgu')
              except Exception as exc:
                  logger.error('Failed to import TLGU: %s', exc)
                  raise
docs: Check if tlgu imported, if not import it.