          return queryset.filter(**filter_kwargs)
  
  
  class UniqueForMonthValidator(BaseUniqueForValidator):
      message = _("This field must be unique for the \"{date_field}\" month.")
  
      def filter_queryset(self, attrs, queryset):
          value = attrs[self.field]
          date = attrs[self.date_field]
  
 
</s> remove     message = _("This field must be unique for the \"{date_field}\" year.")
 </s> add     message = _('This field must be unique for the "{date_field}" year.') </s> remove     message = _("This field must be unique for the \"{date_field}\" date.")
 </s> add     message = _('This field must be unique for the "{date_field}" date.') </s> remove     message = _("This field must be unique.")
 </s> add     message = _('This field must be unique.') </s> remove     message = _("The fields {field_names} must make a unique set.")
    missing_message = _("This field is required.")
 </s> add     message = _('The fields {field_names} must make a unique set.')
    missing_message = _('This field is required.') </s> remove msgid "Invalid version in 'Accept' header."
 </s> add msgid "Invalid version in \"Accept\" header."
    message = _('This field must be unique for the "{date_field}" month.')
          return queryset.filter(**filter_kwargs)
  
  
  class UniqueForMonthValidator(BaseUniqueForValidator):
    message = _('This field must be unique for the "{date_field}" month.')
  
      def filter_queryset(self, attrs, queryset):
          value = attrs[self.field]
          date = attrs[self.date_field]
  
keep keep keep keep replace keep keep keep keep keep
 prefer single quotes in source and double quotes in user visible strings; add some missing full stops to user visible strings 
rest_framework/validators.py