How to use the validators.utils.validator function in validators

@validator
def ipv6_cidr(value):
    """
    Returns whether or not given value is a valid CIDR-notated IP version 6
    address range.

    This validator is based on RFC4632 3.1.

    Examples::

        >>> ipv6_cidr('::1/128')
        True

        >>> ipv6_cidr('::1')
        ValidationFailure(func=ipv6_cidr, args={'value': '::1'})
    """
    try:

@validator
def url(value, public=False):
    """
    Return whether or not given value is a valid URL.

    If the value is valid URL this function returns ``True``, otherwise
    :class:`~validators.utils.ValidationFailure`.

    This validator is based on the wonderful `URL validator of dperini`_.

    .. _URL validator of dperini:
        https://gist.github.com/dperini/729294

    Examples::

        >>> url('http://foobar.dk')
        True

@validator
def ipv4(value):
    """
    Return whether or not given value is a valid IP version 4 address.

    This validator is based on `WTForms IPAddress validator`_

    .. _WTForms IPAddress validator:
       https://github.com/wtforms/wtforms/blob/master/wtforms/validators.py

    Examples::

        >>> ipv4('123.0.0.7')
        True

        >>> ipv4('900.80.70.11')
        ValidationFailure(func=ipv4, args={'value': '900.80.70.11'})

@validator
def iban(value):
    """
    Return whether or not given value is a valid IBAN code.

    If the value is a valid IBAN this function returns ``True``, otherwise
    :class:`~validators.utils.ValidationFailure`.

    Examples::

        >>> iban('DE29100500001061045672')
        True

        >>> iban('123456')
        ValidationFailure(func=iban, ...)

    .. versionadded:: 0.8

@validator
def mac_address(value):
    """
    Return whether or not given value is a valid MAC address.

    If the value is valid MAC address this function returns ``True``,
    otherwise :class:`~validators.utils.ValidationFailure`.

    This validator is based on `WTForms MacAddress validator`_.

    .. _WTForms MacAddress validator:
       https://github.com/wtforms/wtforms/blob/master/wtforms/validators.py

    Examples::

        >>> mac_address('01:23:45:67:ab:CD')
        True

@validator
def email(value, whitelist=None):
    """
    Validate an email address.

    This validator is based on `Django's email validator`_. Returns
    ``True`` on success and :class:`~validators.utils.ValidationFailure`
    when validation fails.

    Examples::

        >>> email('someone@example.com')
        True

        >>> email('bogus@@')
        ValidationFailure(func=email, ...)

@validator
def fi_business_id(business_id):
    """
    Validate a Finnish Business ID.

    Each company in Finland has a distinct business id. For more
    information see `Finnish Trade Register`_

    .. _Finnish Trade Register:
        http://en.wikipedia.org/wiki/Finnish_Trade_Register

    Examples::

        >>> fi_business_id('0112038-9')  # Fast Monkeys Ltd
        True

        >>> fi_business_id('1234567-8')  # Bogus ID

@validator
def truthy(value):
    """
    Validate that given value is not a falsey value.

    This validator is based on `WTForms DataRequired validator`_.

    .. _WTForms DataRequired validator:
       https://github.com/wtforms/wtforms/blob/master/wtforms/validators.py

    Examples::

        >>> truthy(1)
        True

        >>> truthy('someone')
        True

@validator
def uuid(value):
    """
    Return whether or not given value is a valid UUID.

    If the value is valid UUID this function returns ``True``, otherwise
    :class:`~validators.utils.ValidationFailure`.

    This validator is based on `WTForms UUID validator`_.

    .. _WTForms UUID validator:
       https://github.com/wtforms/wtforms/blob/master/wtforms/validators.py

    Examples::

        >>> uuid('2bc1c94f-0deb-43e9-92a1-4775189ec9f8')
        True

@validator
def length(value, min=None, max=None):
    """
    Returns whether or not the length of given string is within a specified
    range.

    Examples::


        >>> assert length('something', min=2)

        >>> assert length('something', min=9, max=9)

        >>> assert not length('something', max=5)


    :param value: