code: def test_selects_for_each_class(self):
      df = pd.DataFrame()
      df["f1"] = [10] * 10 + list(range(10)) + list(range(10))
      df["f2"] = list(range(10)) + [10] * 10 + list(range(10))
      df["f3"] = list(range(10)) + list(range(10)) + [10] * 10
      df["y"] = [0] * 10 + [1] * 10 + [2] * 10
  
      y = df.y
      X = df.drop(["y"], axis=1)
      X_relevant = select_features(X, y, ml_task="classification")
      assert {"f1", "f2", "f3"} == set(X_relevant.columns)
  
file_path: tsfresh/tests/units/feature_selection/test_selection.py
imports: import numpy
  import pandas
  import pytest
  from tsfresh.feature_selection.selection import select_features
label_desc: Use image node_id 7 for calling the TestSelectFeatures obj's underlying member method code with example usage: obj.test_selects_for_each_class() without return types