code: def CheckUnitary(self, x):
      # Tests that x[...,:,:]^H * x[...,:,:] is close to the identity.
      xx = math_ops.matmul(x, x, adjoint_a=True)
      identity = array_ops.matrix_band_part(
          array_ops.ones_like(xx), 0, 0
      )
      tol = 100 * np.finfo(x.dtype).eps
      self.assertAllClose(xx, identity, atol=tol)
  
imports: import itertools
  import unittest
  from absl.testing import parameterized
  import numpy
  from tensorflow.compiler.tests import xla_test
  from tensorflow.python.framework import test_util
  from tensorflow.python.ops import array_ops
  from tensorflow.python.ops import linalg_ops
  from tensorflow.python.ops import math_ops
  from tensorflow.python.platform import test
label_desc: Use image node_id 4 for calling the QrOpTest obj's underlying member method code with example usage: obj.CheckUnitary(x) without return types