def test_pattern_fix_identities_2():
pattern = Required(Optional(Argument('x'), Argument('n')), Argument('n'))
assert pattern.children[0].children[1] == pattern.children[1]
assert pattern.children[0].children[1] is not pattern.children[1]
pattern.fix_identities()
assert pattern.children[0].children[1] is pattern.children[1]
def test_pattern_fix_identities_1():
pattern = Required(Argument('n'), Argument('n'))
assert pattern.children[0] == pattern.children[1]
assert pattern.children[0] is not pattern.children[1]
pattern.fix_identities()
assert pattern.children[0] is pattern.children[1]
