code: def parseJuiceHeaders(lines):
      
      b = JuiceBox()
      bodylen = 0
      key = None
      for L in lines:
          if L[0] == ' ':
              # continuation
              assert key is not None
              b[key] += '\r\n'+L[1:]
              continue
          parts = L.split(': ', 1)
          if len(parts) != 2:
              raise MalformedJuiceBox("Wrong number of parts: %r" % (L,))
          key, value = parts
          key = normalizeKey(key)
          b[key] = value
      return int(b.pop(LENGTH, 0)), b
docs: Create a JuiceBox from a list of header lines.
  
      @param lines: a list of lines.