code: def from_bytes(self, raw):
          '''Return a Null header object reconstructed from raw bytes, or an
          Exception if we can't resurrect the packet.'''
          if len(raw) < 4:
              raise NotEnoughDataError("Not enough bytes ({}) to reconstruct a Null object".format(len(raw)))
          fields = struct.unpack('=I', raw[:4])
          self._af = fields[0]
          return raw[4:f from_bytes(self, raw):
          '''Return a Null header object reconstructed from raw bytes, or an
          Exception if we can't resurrect the packet.'''
          if len(raw) < 4:
              raise NotEnoughDataError("Not enough bytes ({}) to reconstruct a Null object".format(len(raw)))
          fields = struct.unpack('=I', raw[:4])
          self._af = fields[0]
          return raw[4:]
docs: Return a Null header object reconstructed from raw bytes, or an
          Exception if we can't resurrect the packet.