code: def test_1_multiclass_task(self):
      df = pd.read_csv("tests/data/hdi.csv")
      target = "Development Index"
      expected_mixers = [
          "Neural",
          "Regression",
          "RandomForest",
          "XGBoostMixer",
      ]
      mixers = self.get_mixers(df, target)
      self.assertEqual(set(mixers), set(expected_mixers))
  
file_path: lightwood/tests/integration/basic/test_model_selection.py
imports: import unittest
  import pandas
  from lightwood.api.high_level import json_ai_from_problem
  from lightwood.api.types import ProblemDefinition
label_desc: Use image node_id 3 for calling the TestMixerSelection obj's underlying member method code with example usage: obj.test_1_multiclass_task() without return types