code: def parse_http_header(header_line):
      
  
      header_line = header_line.decode().strip()
      col_idx = header_line.find(':')
  
      if col_idx < 1:
          raise BadHttpHeaderError('Bad header: {}'.format(repr(header_line)))
  
      key = header_line[0:col_idx].strip()
      value = header_line[(col_idx+1):].strip()
      return HttpHeader(key=key, value=value)
docs: Parse an HTTP header from a string, and return an ``HttpHeader``.
  
      ``header_line`` should only contain one line.
      ``BadHttpHeaderError`` is raised if the string is an invalid header line.