def test_mul(self):
    t1 = formula.Term('t1')
    t2 = formula.Term('t2')
    f = (t1 * t2)
    assert_(isinstance(f, formula.Formula))
    intercept = formula.Term('intercept')
    f = (t1 * intercept)
    assert_equal(str(f), str(formula.Formula(t1)))
    f = (intercept * t1)
    assert_equal(str(f), str(formula.Formula(t1)))
def test_mul(self):
    t1 = formula.Term('t1')
    t2 = formula.Term('t2')
    f = (t1 * t2)
    assert_(isinstance(f, formula.Formula))
    intercept = formula.Term('intercept')
    f = (t1 * intercept)
    assert_equal(str(f), str(formula.Formula(t1)))
    f = (intercept * t1)
    assert_equal(str(f), str(formula.Formula(t1)))