code: def _create_example_dataframe(cases=5, dimensions=1, length=10):
      """Create a simple data frame set of time series (X) for testing."""
      test_X = pd.DataFrame(dtype=np.float32)
      for i in range(0, dimensions):
          instance_list = []
          for _ in range(0, cases):
              instance_list.append(pd.Series(np.random.randn(length)))
          test_X["dimension_" + str(i)] = instance_list
      return test_X
  
imports: import pickle
  import numpy
  import pandas
  import pytest
  from sklearn.model_selection import KFold
  from sktime.classification.base import BaseClassifier
  from sktime.classification.deep_learning.base import BaseDeepClassifier
  from sktime.classification.distance_based import KNeighborsTimeSeriesClassifier
  from sktime.classification.dummy import DummyClassifier
  from sktime.utils._testing.estimator_checks import _assert_array_almost_equal
  from sktime.utils._testing.panel import _make_classification_y, _make_panel, make_classification_problem
  from sktime.utils.validation._dependencies import _check_soft_dependencies
label_desc: Use image node_id 5 for calling a global function with example usage: _create_example_dataframe(cases, dimensions, length) and returns: test_X