def METHOD_NAME():
    data = TestDatasetMixed()
    loader = MixedLoader(data, batch_size=batch_size, epochs=1, shuffle=False)
    batches = list(loader)
    (x, a, e), y = batches[-1]
    n = data.n_nodes
    assert x.shape == (graphs_in_batch, n, f)
    assert a.shape == (n, n)
    assert e.shape == (graphs_in_batch, data.a.nnz, s)
    assert y.shape == (graphs_in_batch, 2)
    assert loader.steps_per_epoch == np.ceil(len(data) / batch_size)
    signature = loader.tf_signature()
    assert len(signature[0]) == 3