def METHOD_NAME(self, spec):
    spec.write_array(self.__grid)
    # Work out the reciprocal, but zero them if >= 1 as they are not
    # representable as S031 in that case, and not used anyway
    recip = 1 / self.__grid
    recip[recip >= 1.0] = 0
    spec.write_array(DataType.S031.encode_as_numpy_int_array(recip))
    spec.write_value(len(self.__ff_distance_probabilities))
    spec.write_value(len(self.__lat_distance_probabilities))
    spec.write_array(self.__ff_distance_probabilities.view("<u4"))
    spec.write_array(self.__lat_distance_probabilities.view("<u4"))