code: def test_dense(self):
      X = np.random.randint(0, 255, (3, 4))
      Y = CategoryShift().fit_transform(X)
      self.assertTrue((Y == X + 3).all())
  
file_path: auto-sklearn/test/test_pipeline/implementations/test_CategoryShift.py
imports: import numpy
  import scipy.sparse
  from autosklearn.pipeline.implementations.CategoryShift import CategoryShift
  import unittest
label_desc: Use image node_id 1 for calling the CategoryShiftTest obj's underlying member method code with example usage: obj.test_dense() without return types