Approx_itensornetwork() on a rank two tensor yields an error

[JoeyT1994]

If I try to call approx_itensornetwork() on a tensor network T consisting of a single rank two tensor M I get an error.

I.e. the following code:

i = Index(2, "i")
M =  randomITensor(i, i')
M_itn = ITensorNetwork([M])

@show approx_itensornetwork(M_itn, binary_tree_structure(M_itn); alg = "density_matrix")

yields:

But will work if the tensor M has more than two indices.