def __missing__(self, key):
        if self.default_factory is None:
            raise KeyError(key)
        else:
            ret = self[key] = self.default_factory(name=key)
            return ret
def process_weight(sym, arg, aux):
            for stride in RpnParam.anchor_generate.stride:
                add_anchor_to_arg(
                    sym, arg, aux, RpnParam.anchor_generate.max_side,
                    stride, RpnParam.anchor_generate.scale,
                    RpnParam.anchor_generate.ratio)