code: def print_header_content(nlh):
      
      answer = 'type={0} length={1} flags=<{2}> sequence-nr={3} pid={4}'.format(
          nl_nlmsgtype2str(nlh.nlmsg_type, bytearray(), 32).decode('ascii'),
          nlh.nlmsg_len,
          nl_nlmsg_flags2str(nlh.nlmsg_flags, bytearray(), 128).decode('ascii'),
          nlh.nlmsg_seq,
          nlh.nlmsg_pid,
      )
      return answer
docs: Return header content (doesn't actually print like the C library does).
  
      https://github.com/thom311/libnl/blob/libnl3_2_25/lib/handlers.c#L34
  
      Positional arguments:
      nlh -- nlmsghdr class instance.