code: def test_relabel_strings(self, relabel_func, labelarray_dtype):
      class C(Classifier):
          inputs = ()
          dtype = categorical_dtype
          missing_value = None
          window_length = 0
  
      c = C()
  
      raw = np.asarray(
          [
              ["a", "aa", "aaa", "abab"],
              ["bab", "aba", "aa", "bb"],
              ["a", "aba", "abaa", "abaab"],
              ["a", "aa", "aaa", "aaaa"],
          ],
          dtype=labelarray_dtype,
      )
      raw_relabeled = np.vectorize(relabel_func, otypes=[object])(raw)
  
      data = LabelArray(raw, missing_value=None)
  
      terms = {
          "relabeled": c.relabel(relabel_func),
      }
      expected_results = {
          "relabeled": LabelArray(raw_relabeled, missing_value=None),
      }
  
      self.check_terms(
          terms,
          expected_results,
          initial_workspace={c: data},
          mask=self.build_mask(self.ones_mask(shape=data.shape)),
      )
  
imports: from functools import reduce
  import operator
  import numpy
  import pandas
  from zipline.lib.labelarray import LabelArray
  from zipline.pipeline import Classifier
  from zipline.pipeline.data.testing import TestingDataSet
  from zipline.pipeline.expression import methods_to_ops
  from zipline.testing import parameter_space
  from zipline.testing.fixtures import ZiplineTestCase
  from zipline.testing.predicates import assert_equal
  from zipline.utils.numpy_utils import categorical_dtype, int64_dtype
  from .base import BaseUSEquityPipelineTestCase
label_desc: Use image node_id 13 for calling the ClassifierTestCase obj's underlying member method code with example usage: obj.test_relabel_strings(relabel_func, labelarray_dtype) without return types