Validators do not handle null input

[nibsky]

For example in IntegerRangeValidator:

public class IntegerRangeValidator extends CustomValidator<Integer> {

    private IntegerRangeValidator(int min, int max, String errorMessage) {
        super(input -> input >= min && input <= max, errorMessage);
    }
 ....

Could be:

public class IntegerRangeValidator extends CustomValidator<Integer> {

    private IntegerRangeValidator(int min, int max, String errorMessage) {
        super(input -> null != input && input >= min && input <= max, errorMessage);
    }
 ....

Some background on my usage:
I had set the IntegerRangeValidator into a SingleSelectionField (Selection bound to an IntegerProperty).
Due to some design constraint, I needed to change the SingleSelectionField content using SingleSelectionField.items(List).. This part nullifies the bound IntegerProperty until I use SingleSelectionField.select(0).
This causes an unhandled NullPointerException.

Kindly correct me if I overlooked a better approach.