code: def testIter(self):
      @tf.function
      def f(x):
          y, z = x
          return y, z
  
      with self.assertRaises(TypeError):
          f(np.asarray([3, 4]))
  
imports: import numpy
  import tensorflow.compat.v2
  from tensorflow.python.framework import ops
  from tensorflow.python.framework import test_util
  from tensorflow.python.ops.numpy_ops import np_math_ops
label_desc: Use image node_id 3 for calling the FunctionTest obj's underlying member method code with example usage: obj.testIter() and returns: y,  z