code: def testIsNested(self):
      self.assertFalse(nest.is_nested("1234"))
      self.assertFalse(nest.is_nested([1, 3, [4, 5]]))
      self.assertTrue(nest.is_nested(((7, 8), (5, 6))))
      self.assertFalse(nest.is_nested([]))
      self.assertFalse(nest.is_nested(set([1, 2])))
      ones = array_ops.ones([2, 3])
      self.assertFalse(nest.is_nested(ones))
      self.assertFalse(nest.is_nested(math_ops.tanh(ones)))
      self.assertFalse(nest.is_nested(np.ones((4, 5))))
      self.assertTrue(nest.is_nested({"foo": 1, "bar": 2}))
      self.assertFalse(
          nest.is_nested(
              sparse_tensor.SparseTensorValue([[0]], [0], [1])
          )
      )
      self.assertFalse(
          nest.is_nested(
              ragged_factory_ops.constant_value([[[0]], [[1]]])
          )
      )
  
imports: import collections
  import dataclasses
  from absl.testing import parameterized
  import numpy
  from tensorflow.python.data.kernel_tests import test_base
  from tensorflow.python.data.util import nest
  from tensorflow.python.framework import combinations
  from tensorflow.python.framework import constant_op
  from tensorflow.python.framework import sparse_tensor
  from tensorflow.python.framework import tensor
  from tensorflow.python.ops import array_ops
  from tensorflow.python.ops import math_ops
  from tensorflow.python.ops.ragged import ragged_factory_ops
  from tensorflow.python.platform import test
label_desc: Use image node_id 13 for calling the NestTest obj's underlying member method code with example usage: obj.testIsNested() without return types