code: def test_matmul():
      x = torch.rand(5, 2)
      y = torch.rand(2, 4)
      enc_x = pk.encrypt_tensor(x)
      enc_z = torch.matmul(enc_x, y)
      z = sk.decrypt_tensor(enc_z)
      assert torch.allclose(z, torch.matmul(x, y))
  
file_path: FATE/python/fate/test/test_vertor_paillier.py
imports: import torch
  from fate.arch import Context
label_desc: Use image node_id 5 for calling a global function with example usage: test_matmul() without return types