Commons Lang、Validate.noNullElements()

import org.apache.commons.lang.Validate;

public class C2009051400 {
    public static void main(String[] args) {
        String[] str_list1 = {"foo", "bar", "baz"};
        Validate.noNullElements(str_list1);

        String[] str_list2 = {"foo", "bar", "baz", null};
        Validate.noNullElements(str_list2);
    }
}

で、

Exception in thread "main" java.lang.IllegalArgumentException: The validated array contains null element at index: 3
        at org.apache.commons.lang.Validate.noNullElements(Validate.java:435)
        at C2009051400.main(C2009051400.java:10)