def test_unwrap_preserve():
inner_expression = Expression()
inner_expression.append(Unit(10))
inner_expression.append(Unit(20))
assert utils.unwrap(inner_expression) == inner_expression
outer_expression = Expression()
outer_expression.preserve = True
outer_expression.append(inner_expression)
assert utils.unwrap(outer_expression) == outer_expression
def test_expression_make_is_list_and_preserve():
expression = Expression()
expression.is_list = True
expression.preserve = True
assert expression.is_list
assert expression.preserve