code: def test_dlpack():
      # test dlpack conversion.
      def nd2th():
          ans = np.array(
              [
                  [1.0, 1.0, 1.0, 1.0],
                  [0.0, 0.0, 0.0, 0.0],
                  [0.0, 0.0, 0.0, 0.0],
              ]
          )
          x = nd.array(np.zeros((3, 4), dtype=np.float32))
          dl = x.to_dlpack()
          y = F.zerocopy_from_dlpack(dl)
          y[0] = 1
          print(x)
          print(y)
          assert np.allclose(x.asnumpy(), ans)
  
      def th2nd():
          ans = np.array(
              [
                  [1.0, 1.0, 1.0, 1.0],
                  [0.0, 0.0, 0.0, 0.0],
                  [0.0, 0.0, 0.0, 0.0],
              ]
          )
          x = F.zeros((3, 4))
          dl = F.zerocopy_to_dlpack(x)
          y = nd.from_dlpack(dl)
          x[0] = 1
          print(x)
          print(y)
          assert np.allclose(y.asnumpy(), ans)
  
      def th2nd_incontiguous():
          x = F.astype(F.tensor([[0, 1], [2, 3]]), F.int64)
          ans = np.array([0, 2])
          y = x[:2, 0]
          # Uncomment this line and comment the one below to observe error
          # dl = dlpack.to_dlpack(y)
          dl = F.zerocopy_to_dlpack(y)
          z = nd.from_dlpack(dl)
          print(x)
          print(z)
          assert np.allclose(z.asnumpy(), ans)
  
      nd2th()
      th2nd()
      th2nd_incontiguous()
  
imports: import unittest
  import backend
  import dgl
  import dgl.ndarray
  import numpy
label_desc: Use image node_id 1 for calling a global function with example usage: test_dlpack() without return types