code: def test_matmul(self):
      computed = tf_i128.from_i128(
          tf_i128.right_shift(
              tf_i128.matmul(self.A, self.C), self.precision_bits
          ),
          self.scale,
      )
      ground = self._A.dot(self._C)
  
      self.assertTrue(np.allclose(computed, ground), "wrong mat_mul")
      self.assertTrue(
          computed.shape == ground.shape, "wrong mat_mul shape"
      )
  
imports: import unittest
  import numpy
  import tensorflow
  from tf_encrypted.operations import tf_i128
label_desc: Use image node_id 5 for calling the I128TestCase obj's underlying member method code with example usage: obj.test_matmul() without return types