code: def test_check_cv(self):
      iris = datasets.load_iris()
  
      df = pdml.ModelFrame(iris)
      result = df.model_selection.check_cv(cv=5)
      self.assertIsInstance(result, ms.KFold)
  
imports: import sklearn.datasets
  import sklearn.svm
  import sklearn.naive_bayes
  import numpy
  import pandas
  import pandas_ml
  import pandas_ml.util.testing
label_desc: Use image node_id 9 for calling the TestSplitter obj's underlying member method code with example usage: obj.test_check_cv() without return types