def get_stem_fun(stem_type):
    """Retrives the stem function by name."""
    stem_funs = {
        "res_stem_cifar": ResStemCifar,
        "res_stem_in": ResStemIN,
        "simple_stem_in": SimpleStemIN,
    }
    assert stem_type in stem_funs.keys(), "Stem type '{}' not supported".format(
        stem_type
    )
    return stem_funs[stem_type]
Retrives the stem function by name.
fastreid/modeling/backbones/regnet/regnet.py