def test_simple_paranthesis():
assert validate("()")
def test_empty_input():
assert validate("")
def test_performance():
start = time.time()
validate("(()" * 20)
end = time.time()
assert end - start < 1
def test_foo_bar():
assert validate("()[]")
assert validate("{()}[[{}]]")
def test_unbalanced():
assert not validate("{{)(}}")
def test_nested_parens():
assert validate("([])")
def test_double_xxxxx():
assert not validate("())")
def test_double_parenthesis():
assert not validate("([)]")
def test_simple_paranthesis():
assert not validate(")(")
def test_simple_negative():
assert not validate("(")