  
          filter_kwargs = {}
          filter_kwargs[self.field_name] = value
          filter_kwargs['%s__year' % self.date_field_name] = date.year
          return queryset.filter(**filter_kwargs)
 
</s> remove         return queryset.filter(**filter_kwargs)
 </s> add         return qs_filter(queryset, **filter_kwargs) </s> remove         return queryset.filter(**filter_kwargs)
 </s> add         return qs_filter(queryset, **filter_kwargs) </s> remove         if queryset.exists():
 </s> add         if qs_exists(queryset): </s> remove         if None not in checked_values and queryset.exists():
 </s> add         if None not in checked_values and qs_exists(queryset): </s> remove         return queryset.filter(**filter_kwargs)
 </s> add         return qs_filter(queryset, **filter_kwargs)
        return qs_filter(queryset, **filter_kwargs)
  
          filter_kwargs = {}
          filter_kwargs[self.field_name] = value
          filter_kwargs['%s__year' % self.date_field_name] = date.year
        return qs_filter(queryset, **filter_kwargs)
keep keep keep keep replace
 Robust uniqueness checks. (#4217)

* Robust uniqueness checks
* Add master to test matrix (allow_failures) 
rest_framework/validators.py