def add(self, elem, replace=False):
        """Add a requirement.

        :param elem: a string or :class:`Requirement` instance.
        :param replace: if `True`, packages in the set with the same name will
            be removed first.
        """
        if isinstance(elem, text_type):
            elem = Requirement.coerce(elem)
        if replace and elem in self:
            self.remove(elem)
        super(Requirements, self).add(elem)
def approve(self, user_id=None, service=""):
        """
        Approve the verification attempt for user

        Valid attempt statuses when calling this method:
            `submitted`, `approved`, `denied`

        After method completes:
            status is set to `approved`
            expiry_date is set to one year from now
        """
        self.expiry_date = now() + timedelta(
            days=settings.VERIFY_STUDENT["DAYS_GOOD_FOR"]
        )
        super(SoftwareSecurePhotoVerification, self).approve(user_id, service)