the `adj_x` or `adj_y` flag to `True`, which are by default `False`.

The input tensors `x` and `y` are 2-D or higher with shape `[..., r_x, c_x]`
and `[..., r_y, c_y]`.

The output tensor is 2-D or higher with shape `[..., r_o, c_o]`, where:

    r_o = c_x if adj_x else r_x
    c_o = r_y if adj_y else c_y

It is computed as:

    output[..., :, :] = matrix(x[..., :, :]) * matrix(y[..., :, :])