def METHOD_NAME():
    dev = F.ctx()
    row = torch.tensor([1, 0, 0, 0, 1]).to(dev)
    col = torch.tensor([1, 1, 1, 2, 2]).to(dev)
    val = torch.randn(len(row)).to(dev)
    shape = (4, 4)
    A1 = from_coo(row, col, val, shape)
    row = torch.tensor([1, 0, 0, 1]).to(dev)
    col = torch.tensor([1, 1, 2, 2]).to(dev)
    val = torch.randn(len(row)).to(dev)
    shape = (4, 4)
    A2 = from_coo(row, col, val, shape)
    try:
        matmul(A1, A2)
    except:
        pass
    else:
        assert False, "Should raise error."
    try:
        matmul(A2, A1)
    except:
        pass
    else:
        assert False, "Should raise error."