Created by: Xreki

See here, the second case:

x is a Tensor:
    x.data = [[a], [b], [c]]
    x.dims = [3, 1]

y is a LoDTensor:
    y.lod = [[2, 0, 3]]

ref_level: -1

then output is a Tensor:
    out.data = [[a], [a], [c], [c], [c]]
    out.dims = [5, 1]

y.lod should be [[0, 2, 2, 5]]?