docs: def parse_multi_value_header(header_str):
      """Break apart an HTTP header string that is potentially a quoted, comma separated list as used in entity headers in RFC2616."""
      parsed_parts = []
      if header_str:
          parts = header_str.split(',')
          for part in parts:
              match = re.search('\s*(W/)?\"?([^"]*)\"?\s*', part)
              if match is not None:
                  parsed_parts.append(match.group(2))
      return parsed_parts