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 reverse(self, request, view_name):
        """
        Returns the URL of this tenant.
        """
        http_type = 'https://' if request.is_secure() else 'http://'

        domain = get_current_site(request).domain

        url = ''.join((http_type, self.schema_name, '.', domain, reverse(view_name)))

        return url