I need to make a queryset on django and I want to filter both a model and its related model. Like I need to get all PartRequest's that are created by a seller and I want to retrieve only his bid attatched.

```
class PartRequest(models.Model):

class Bid(models.Model):

    seller      = models.ForeignKey(UserSeller, related_name='seller_bid')
    request     = models.ForeignKey(PartRequest, related_name='request_bid')

```