code: def mtf_bitransformer_tiny():
    
    hparams = mtf_bitransformer_base()
    hparams.batch_size = 2
    hparams.mesh_shape = ""
    hparams.d_model = 128
    hparams.encoder_layers = ["self_att", "drd"] * 2
    hparams.decoder_layers = ["self_att", "enc_att", "drd"] * 2
    hparams.num_heads = 4
    hparams.d_ff = 512
    return hparams
docs: Small encoder-decoder model for testing.