code: def test_5_timeseries_t_plus_n(self):
      df = pd.read_csv("tests/data/arrivals.csv")
      target = "Traffic"
      prob_kwargs = {
          "time_aim": 15,
          "timeseries_settings": {
              "group_by": ["Country"],
              "horizon": 3,
              "order_by": "T",
              "window": 5,
          },
      }
      expected_mixers = ["NeuralTs", "XGBoostArrayMixer"]
      mixers = self.get_mixers(df, target, prob_kwargs=prob_kwargs)
      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 7 for calling the TestMixerSelection obj's underlying member method code with example usage: obj.test_5_timeseries_t_plus_n() without return types