          for field_name, relation_info in info.forward_relations.items():
              if self.opts.depth:
                  ret[field_name] = self.get_nested_field(*relation_info)
              else:
                  ret[field_name] = self.get_related_field(*relation_info)
  
          # Reverse relations
          for accessor_name, relation_info in info.reverse_relations.items():
              if accessor_name in self.opts.fields:
                  if self.opts.depth:
 
</s> remove                 ret[field_name] = self.get_nested_field(*relation_info)
 </s> add                 ret[field_name] = self.get_nested_field(field_name, *relation_info) </s> remove                     ret[accessor_name] = self.get_nested_field(*relation_info)
 </s> add                     ret[accessor_name] = self.get_nested_field(accessor_name, *relation_info) </s> remove             ret[field_name] = self.get_field(field)
 </s> add             ret[field_name] = self.get_field(field_name, field) </s> remove                     ret[accessor_name] = self.get_related_field(*relation_info)
 </s> add                     ret[accessor_name] = self.get_related_field(accessor_name, *relation_info) </s> remove             ret[info.pk.name] = serializer_pk_field
 </s> add             ret[field_name] = serializer_pk_field
                ret[field_name] = self.get_related_field(field_name, *relation_info)
          for field_name, relation_info in info.forward_relations.items():
              if self.opts.depth:
                  ret[field_name] = self.get_nested_field(*relation_info)
              else:
                ret[field_name] = self.get_related_field(field_name, *relation_info)
  
          # Reverse relations
          for accessor_name, relation_info in info.reverse_relations.items():
              if accessor_name in self.opts.fields:
                  if self.opts.depth:
keep keep keep keep replace keep keep keep keep keep
 Drop label from serializer fields when not needed 
rest_framework/serializers.py