code: def test_adagrad_classes_multiclass(train_data):
      X, y = train_data
      clf = AdaGradClassifier()
      assert not hasattr(clf, "classes_")
      clf.fit(X, y)
      assert list(clf.classes_) == [0, 1, 2]
  
file_path: lightning/lightning/impl/tests/test_adagrad.py
imports: import numpy
  import pytest
  from lightning.classification import AdaGradClassifier
  from lightning.regression import AdaGradRegressor
  from lightning.impl.adagrad_fast import _proj_elastic_all
  from lightning.impl.tests.utils import check_predict_proba
label_desc: Use image node_id 6 for calling a global function with example usage: test_adagrad_classes_multiclass(train_data) without return types