code: def urljoin_safe(base_url, url, allow_fragments=True):
      '''urljoin with warning log on error.
  
      Returns:
          str, None'''
      try:
          return wpull.url.urljoin(
              base_url, url, allow_fragments=allow_fragments
          )
      except ValueError as error:
          _logger.warning(__(
              _('Unable to parse URL ‘{url}’: {error}.'),
              url=url, error=error
          )f urljoin_safe(base_url, url, allow_fragments=True):
      '''urljoin with warning log on error.
  
      Returns:
          str, None'''
      try:
          return wpull.url.urljoin(
              base_url, url, allow_fragments=allow_fragments
          )
      except ValueError as error:
          _logger.warning(__(
              _('Unable to parse URL ‘{url}’: {error}.'),
              url=url, error=error
          ))
docs: urljoin with warning log on error.
  
      Returns:
          str, None