          Creates a default instance of a basic non-relational field.
          """
          kwargs = {}
  
          kwargs['blank'] = model_field.blank
  
          if model_field.null or model_field.blank:
              kwargs['required'] = False
  
          if isinstance(model_field, models.AutoField) or not model_field.editable:
              kwargs['read_only'] = True
  
 
</s> remove         if model_field.has_default():
            kwargs['required'] = False
 </s> add         if has_default: </s> remove     target = serializers.SlugRelatedField(slug_field='name', null=True)
 </s> add     target = serializers.SlugRelatedField(slug_field='name', required=False) </s> remove             title = serializers.CharField(blank=True)
 </s> add             title = serializers.CharField(required=False)
        if model_field.null or model_field.blank or has_default:
          Creates a default instance of a basic non-relational field.
          """
          kwargs = {}
  
        if model_field.null or model_field.blank or has_default:
        if model_field.null or model_field.blank or has_default:
        if model_field.null or model_field.blank or has_default:
              kwargs['required'] = False
  
          if isinstance(model_field, models.AutoField) or not model_field.editable:
              kwargs['read_only'] = True
  
keep keep keep keep replace replace replace keep keep keep keep keep
 Use new style of `required=<bool>` not `blank` or `null` 
rest_framework/serializers.py