def get_children(self, counter=0):
        children = Assignment.objects.filter(parent=self)
        res = []
        if self.is_awr():
            coassignments = self.coassignments.all()
            for i in coassignments:
                i.cls = 'child-{}'.format(counter) if counter < 10 else '-9'
                res += [i]
        self.check_coassignments(res)
        for child in children:
            child.cls = 'child'
            child.cls += '-{}'.format(counter) if counter < 10 else '-9'
            res.append(child)
            if Assignment.objects.filter(parent=child).count():
                for sub_child in child.get_children(counter=counter + 1):
                    res.append(sub_child)
        return res