code: def test_relabel_missing_value_interactions(self, missing_value):
      mv = missing_value
  
      class C(Classifier):
          inputs = ()
          dtype = categorical_dtype
          missing_value = mv
          window_length = 0
  
      c = C()
  
      def relabel_func(s):
          if s == "B":
              return mv
          return "".join([s, s])
  
      raw = np.asarray(
          [
              ["A", "B", "C", mv],
              [mv, "A", "B", "C"],
              ["C", mv, "A", "B"],
              ["B", "C", mv, "A"],
          ],
          dtype=categorical_dtype,
      )
      data = LabelArray(raw, missing_value=mv)
  
      expected_relabeled_raw = np.asarray(
          [
              ["AA", mv, "CC", mv],
              [mv, "AA", mv, "CC"],
              ["CC", mv, "AA", mv],
              [mv, "CC", mv, "AA"],
          ],
          dtype=categorical_dtype,
      )
  
      terms = {
          "relabeled": c.relabel(relabel_func),
      }
      expected_results = {
          "relabeled": LabelArray(
              expected_relabeled_raw, missing_value=mv
          ),
      }
  
      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 14 for calling the ClassifierTestCase obj's underlying member method code with example usage: obj.test_relabel_missing_value_interactions(missing_value) and returns: str, mv