code: def testAssignUpdateNoShape(self):
      var = state_ops.variable_op(
          [1, 2], dtypes.float32, set_shape=False
      )
      added = state_ops.assign_add(var, self._NewShapelessTensor())
      self.assertEqual(tensor_shape.unknown_shape(), added.get_shape())
      subbed = state_ops.assign_sub(var, self._NewShapelessTensor())
      self.assertEqual(tensor_shape.unknown_shape(), subbed.get_shape())
  
imports: import numpy
  from tensorflow.python.framework import dtypes
  from tensorflow.python.framework import errors
  from tensorflow.python.framework import ops
  from tensorflow.python.framework import tensor_shape
  from tensorflow.python.framework import test_util
  from tensorflow.python.ops import array_ops
  from tensorflow.python.ops import array_ops_stack
  from tensorflow.python.ops import gen_state_ops
  from tensorflow.python.ops import math_ops
  from tensorflow.python.ops import state_ops
  from tensorflow.python.ops import variable_v1
  from tensorflow.python.ops import variables
  from tensorflow.python.platform import test
label_desc: Use image node_id 17 for calling the VariableOpTest obj's underlying member method code with example usage: obj.testAssignUpdateNoShape() without return types