def METHOD_NAME():
    X = pd.DataFrame({})
    y = pd.Series(["a", "b", "c", "a"])
    encoder = LabelEncoder()
    X_fit_transformed, y_fit_transformed = encoder.fit_transform(X, y)
    encoder_duplicate = LabelEncoder()
    encoder_duplicate.fit(X, y)
    X_transformed, y_transformed = encoder_duplicate.transform(X, y)
    assert_frame_equal(X_fit_transformed, X_transformed)
    assert_series_equal(y_fit_transformed, y_transformed)