def _register_make(cls):
 assert (cls.nxm_headers is not None)
 assert (cls.nxm_headers is not [])
 for nxm_header in cls.nxm_headers:
  assert (nxm_header not in _MF_FIELDS)
  _MF_FIELDS[nxm_header] = cls.make
 return cls

def _register_make ( cls ) : assert ( cls . nxm_headers is not None ) assert ( cls . nxm_headers is not [ ] ) for nxm_header in cls . nxm_headers : assert ( nxm_header not in _MF_FIELDS ) _MF_FIELDS [ nxm_header ] = cls . make return cls
class decorator to register mf make .