fix forgotten doctest
@@ -479,7 +479,7 @@ pub fn derive_query_id(input: TokenStream) -> TokenStream {
/// type Row = String;
///
/// fn build(s: String) -> deserialize::Result<Self> {
-/// LowercaseString(s.to_lowercase())
+/// Ok(LowercaseString(s.to_lowercase()))
/// }
/// }
///
