code: def parse_OWS(header: str, pos: int) -> int:
      
      # There's always a match, possibly empty, whose content doesn't matter.
      match = _OWS_re.match(header, pos)
      assert match is not None
      return match.end()
docs: Parse optional whitespace from ``header`` at the given position.
  
      Return the new position.
  
      The whitespace itself isn't returned because it isn't significant.