public interface Comparator {
    boolean isLessThan(Object a, Object b) throws ComparatorException;
    boolean isLessThanOrEqualTo(Object a, Object b) throws ComparatorException;
    boolean isEqualTo(Object a, Object b) throws ComparatorException;
    boolean isGreaterThan(Object a, Object b) throws ComparatorException;
    boolean isGreaterThanOrEqualTo(Object a, Object b) throws ComparatorException;
    boolean isComparable(Object a);
}