@@ -0,0 +1,376 @@
+package net.sf.kerner.utils.collections.impl;%0A%0Aimport java.util.Comparator;%0A%0Apublic abstract class ComparatorNull%3CT%3E implements Comparator%3CT%3E%7B%0A%0A%09public int compare(T o1, T o2) %7B%0A%09%09if (o1 == null && o2 == null)%0A%09%09%09return 0;%0A%09%09if (o1 == null)%0A%09%09%09return -1;%0A%09%09if (o2 == null)%0A%09%09%09return 1;%0A%09%09return compareNonNull(o1, o2);%0A%09%7D%0A%09%0A%09public abstract int compareNonNull(T o1, T o2);%0A%0A%7D%0A

Introduce ComparatorNull.