code: def test_prepare_data():
      data = prepare_data()
      assert len(data) == 4
      x_train, x_test, y_train, y_test = data
      assert len(x_train) == 112
      assert len(x_test) == 38
      assert len(y_train) == 112
      assert len(y_test) == 38
  
imports: import warnings
  from sklearn.datasets import load_iris
  from sklearn.model_selection import train_test_split
  from sklearn import preprocessing
label_desc: Use image node_id 2 for calling a global function with example usage: test_prepare_data() without return types