code: def query_all(self):
          
          if DJANGO_20_PLUS:
              obj = self._clone()
          else:
              obj = self._clone(klass=SalesforceQuerySet)  # pylint: disable=unexpected-keyword-arg
          obj.query.set_query_all()
          return obj
docs: Allows querying for also deleted or merged records.
              Lead.objects.query_all().filter(IsDeleted=True,...)
          https://www.salesforce.com/us/developer/docs/api_rest/Content/resources_queryall.htm