def _run_step(network, X_batch, y_batch, cost=None, acc=None):
    """Run for one step"""
    y_pred = network(X_batch)
    _loss, _acc = None, None
    if cost is not None:
        _loss = cost(y_pred, y_batch)
    if acc is not None:
        _acc = acc(y_pred, y_batch)
    return _loss, _acc
