code: def test_data_type_consistency(self):
      X = np.random.randint(0, 255, (3, 4))
      Y = CategoryShift().fit_transform(X)
      self.assertFalse(scipy.sparse.issparse(Y))
  
      X = scipy.sparse.csc_matrix(
          ([1, 2, 0, 4], ([0, 1, 2, 1], [3, 2, 1, 0])), shape=(3, 4)
      )
      Y = CategoryShift().fit_transform(X)
      self.assertTrue(scipy.sparse.issparse(Y))
  
imports: import numpy
  import scipy.sparse
  from autosklearn.pipeline.components.data_preprocessing.category_shift.category_shift 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_data_type_consistency() without return types