code: def dump_attr(ofd, attr, prefix=0):
      
      dump_hex(ofd, nla_data(attr), nla_len(attr), prefix)
docs: https://github.com/thom311/libnl/blob/libnl3_2_25/lib/msg.c#L862.
  
      Positional arguments:
      ofd -- function to call with arguments similar to `logging.debug`.
      attr -- nlattr class instance.
  
      Keyword arguments:
      prefix -- additional number of whitespace pairs to prefix each log statement with.