code: def test_dataset_no_index():
      ds = dataset_from_dict({"col1": [1, 2, 3, 4, 10, 11]})
      assert_that(
          calling(DateTrainTestLeakageDuplicates().run).with_args(
              ds, ds
          ),
          raises(
              DatasetValidationError,
              "Dataset does not contain a datetime",
          ),
      )
      assert_that(
          calling(DateTrainTestLeakageOverlap().run).with_args(ds, ds),
          raises(
              DatasetValidationError,
              "Dataset does not contain a datetime",
          ),
      )
  
imports: from datetime import datetime
  import numpy
  import pandas
  from hamcrest import assert_that, calling, close_to, equal_to, greater_than, has_items, has_length, raises
  from deepchecks.core.errors import DatasetValidationError, DeepchecksValueError
  from deepchecks.tabular.checks.train_test_validation import DateTrainTestLeakageDuplicates, DateTrainTestLeakageOverlap
  from deepchecks.tabular.dataset import Dataset
  from tests.base.utils import equal_condition_result
label_desc: Use image node_id 7 for calling a global function with example usage: test_dataset_no_index() without return types