def test_ipv6_validation_failure():
"""
Test function returns False if invalid IPv4 address is specified
"""
assert not is_ipv6('2001::0234:C1ab::A0:aabc:003F')
def test_ipv6_validation_success():
"""
Test function returns True if valid IPv4 address is specified
"""
assert is_ipv6('2001:db8::ff00:42:8329')
