code: def testUnknownShape(self):
      x = array_ops.placeholder(dtypes.float32)
      num_dimensions = array_ops.placeholder(dtypes.int32)
      ret = random_grad.add_leading_unit_dimensions(x, num_dimensions)
      with self.cached_session() as sess:
          ret_val = sess.run(
              ret, {x: np.ones([2, 2]), num_dimensions: 2}
          )
      self.assertAllEqual(ret_val.shape, [1, 1, 2, 2])
  
imports: import numpy
  from tensorflow.python.framework import constant_op
  from tensorflow.python.framework import dtypes
  from tensorflow.python.framework import test_util
  from tensorflow.python.ops import array_ops
  from tensorflow.python.ops import gen_stateless_random_ops_v2
  from tensorflow.python.ops import gradients_impl
  from tensorflow.python.ops import math_ops
  from tensorflow.python.ops import random_grad
  from tensorflow.python.ops import random_ops
  from tensorflow.python.platform import test
  from tensorflow.python.platform import tf_logging
label_desc: Use image node_id 4 for calling the AddLeadingUnitDimensionsTest obj's underlying member method code with example usage: obj.testUnknownShape() without return types