code: def test_union1d_3(self, xp):
      x = xp.zeros((2, 2), dtype=xp.complex_)
      y = xp.array([[1 + 1j, 2 + 3j], [4 + 1j, 0 + 7j]])
      return xp.union1d(x, y)
  
imports: import warnings
  import numpy
  from cupy import testing
label_desc: Use image node_id 3 for calling the TestUnion1d obj's underlying member method code with example usage: obj.test_union1d_3(xp) and returns: xp