def remove(self, elem):
        """Remove a requirement.

        :param elem: a string or :class:`Requirement` instance.
        """
        if isinstance(elem, text_type):
            for requirement in self:
                if requirement.package == elem:
                    return super(Requirements, self).remove(requirement)
        return super(Requirements, self).remove(elem)
def detail_export(self, request, pk=None):
        serializer = ConditionExportSerializer(self.get_object())
        xml = ConditionRenderer().render([serializer.data])
        return XMLResponse(xml, name=self.get_object().key)