text: import sys, shutil
  sys.path.insert(1, "../../../")
  import h2o, tests
  
  def cars_checkpoint():
  
      cars = h2o.upload_file(tests.locate("smalldata/junit/cars_20mpg.csv"))
      predictors = ["displacement","power","weight","acceleration","year"]
      response_col = "economy"
  
      # build first model
      model1 = h2o.random_forest(x=cars[predictors],y=cars[response_col],ntrees=10,max_depth=2, min_rows=10)
  
      # continue building the model
      model2 = h2o.random_forest(x=cars[predictors],y=cars[response_col],ntrees=11,max_depth=3, min_rows=9,r2_stopping=0.8,
                                 checkpoint=model1._id)
  
      #   erroneous, not MODIFIABLE_BY_CHECKPOINT_FIELDS
      # PUBDEV-1833
  
      #   mtries
      try:
          model = h2o.random_forest(y=cars[response_col], x=cars[predictors],mtries=2,checkpoint=model1._id)
          assert False, "Expected model-build to fail because mtries not modifiable by checkpoint"
      except EnvironmentError:
          assert True
  
      #   sample_rate
      try:
          model = h2o.random_forest(y=cars[response_col], x=cars[predictors],sample_rate=0.5,checkpoint=model1._id)
          assert False, "Expected model-build to fail because sample_rate not modifiable by checkpoint"
      except EnvironmentError:
          assert True
  
      #   nbins_cats
      try:
          model = h2o.random_forest(y=cars[response_col], x=cars[predictors],nbins_cats=99,checkpoint=model1._id)
          assert False, "Expected model-build to fail because nbins_cats not modifiable by checkpoint"
      except EnvironmentError:
          assert True
  
      #   nbins
      try:
          model = h2o.random_forest(y=cars[response_col], x=cars[predictors],nbins=99,checkpoint=model1._id)
          assert False, "Expected model-build to fail because nbins not modifiable by checkpoint"
      except EnvironmentError:
          assert True
  
      #   balance_classes
      try:
          model = h2o.random_forest(y=cars[response_col], x=cars[predictors],balance_classes=True,checkpoint=model1._id)
          assert False, "Expected model-build to fail because balance_classes not modifiable by checkpoint"
      except EnvironmentError:
          assert True
  
      #   nfolds
      try:
          model = h2o.random_forest(y=cars[response_col], x=cars[predictors],nfolds=3,checkpoint=model1._id)
          assert False, "Expected model-build to fail because nfolds not modifiable by checkpoint"
      except EnvironmentError:
          assert True
  
  
  if __name__ == "__main__":
      tests.run_test(sys.argv, cars_checkpoint)
  