Returns a namedtuple (values, indices) where values is the median
value of each row of the input tensor in the given dimension
dim. And indices is the index location of each median value found.
By default, dim is the last dimension of the input tensor.
If keepdim is TRUE, the output tensors are of the same size
as input except in the dimension dim where they are of size 1.
Otherwise, dim is squeezed (see torch_squeeze), resulting in
the outputs tensor having 1 fewer dimension than input.