code: def test_FunctionTransformer(self):
      iris = datasets.load_iris()
      df = pdml.ModelFrame(iris)
  
      mod1 = df.pp.FunctionTransformer(func=lambda x: x + 1)
      df.fit(mod1)
      result = df.transform(mod1)
  
      exp = df.copy()
      exp.data = exp.data + 1
  
      self.assertIsInstance(result, pdml.ModelFrame)
      tm.assert_frame_equal(result, exp)
  
imports: import pytest
  import numpy
  import pandas
  import sklearn.datasets
  import sklearn.preprocessing
  import pandas_ml
  import pandas_ml.util.testing
label_desc: Use image node_id 15 for calling the TestPreprocessing obj's underlying member method code with example usage: obj.test_FunctionTransformer() without return types