code: def _parse_requestline(line):
          
          m = re.match(r'({})\s+(.*)\s+HTTP/(1.[0|1])'.format('|'.join(Entry.METHODS)), line, re.I)
          if m:
              return m.group(1).upper(), m.group(2), m.group(3)
          else:
              raise ValueError('Not a Request-Line')
docs: http://www.w3.org/Protocols/rfc2616/rfc2616-sec5.html#sec5
  
          >>> Entry._parse_requestline('GET / HTTP/1.0') == ('GET', '/', '1.0')
          True
          >>> Entry._parse_requestline('post /testurl htTP/1.1') == ('POST', '/testurl', '1.1')
          True
          >>> Entry._parse_requestline('Im not a RequestLine')
          Traceback (most recent call last):
              ...
          ValueError: Not a Request-Line