code: def _setup_language_variables(self):
          
          if self.language not in AVAILABLE_LANGUAGES:
              # If no official repos, check if user has custom
              user_defined_corpora = self._check_distributed_corpora_file()
              if user_defined_corpora:
                  return user_defined_corpora
              else:
                  msg = 'Corpora not available (either core or user-defined) for the "{}" language.'.format(self.language)
                  logger.info(msg)
                  raise CorpusImportError(msg)
          else:
              user_defined_corpora = self._check_distributed_corpora_file()
              return user_defined_corpora
docs: Check for availability of corpora for a language.
          TODO: Make the selection of available languages dynamic from dirs
          within ``corpora`` which contain a ``corpora.py`` file.