[ 0., -0.,  1.]])
      >>> a = torch.randn(3, 4, 5)
      >>> q, r = torch.qr(a, some=False)
      >>> torch.allclose(torch.matmul(q, r), a)
      True
      >>> torch.allclose(torch.matmul(q.mT, q), torch.eye(5))
      True