code: def testFlatMap(self):
      cluster = data_service_test_base.TestCluster(num_workers=2)
      elements = [1, 5, 0]
      ds = dataset_ops.Dataset.from_tensor_slices(elements)
      ds = ds.flat_map(
          lambda x: dataset_ops.Dataset.from_tensor_slices([x])
      )
      ds = self._make_dynamic_sharding_dataset(ds, cluster)
      self.assertDatasetProduces(ds, elements, assert_items_equal=True)
  
imports: import collections
  from absl.testing import parameterized
  import numpy
  from tensorflow.python.data.experimental.kernel_tests.service import test_base
  from tensorflow.python.data.experimental.ops import data_service_ops
  from tensorflow.python.data.kernel_tests import test_base
  from tensorflow.python.data.kernel_tests import tf_record_test_base
  from tensorflow.python.data.ops import dataset_ops
  from tensorflow.python.data.ops import readers
  from tensorflow.python.framework import combinations
  from tensorflow.python.framework import errors
  from tensorflow.python.ops import math_ops
  from tensorflow.python.ops import random_ops
  from tensorflow.python.platform import test
label_desc: Use image node_id 7 for calling the DynamicShardingTest obj's underlying member method code with example usage: obj.testFlatMap() without return types