我正在用django_filters过滤我的Department模型。但它提出了太多的疑问。我该怎么解决？

# models.py

class Branch(models.Model):
    name = models.CharField(max_length=100)

    class Meta:
        verbose_name_plural = "Branches"

    def __str__(self):
        return self.name

class Department(models.Model):
    name = models.CharField(max_length=100)
    branch = models.ManyToManyField(Branch, related_name="department")

    def __str__(self):
        return self.name

_

# views.py

class DepartmentListAPIView(generics.ListAPIView):
    queryset = Department.objects.all()
    serializer_class = DepartmentSerializer
    filter_backends = (filters.DjangoFilterBackend,)
    filterset_class = DepartmentFilter

_

# serializers.py

class DepartmentSerializer(serializers.ModelSerializer):
    class Meta:
        model = Department
        fields = "__all__"

_

# filters.py

class DepartmentFilter(filters.FilterSet):
    branch = filters.CharFilter(field_name="branch__id", lookup_expr="in")

    class Meta:
        model = Department
        fields = "__all__"