Relax the constraint to allow null default values for converter
@@ -41,7 +41,7 @@ public interface Specifying<T extends Specifying<T>> {
* The default value to use when the object cannot be converted or in case
* of conversion from a {@code null} value.
*
- * @param defVal The default value, must not be {@code null}.
+ * @param defVal The default value.
* @return The current {@code Converting} object so that additional calls
* can be chained.
*/
