src/main/java/org/organicdesign/fp/collections/PersistentTreeMap.java
@Override public Comparator<? super K> comparator() {
        return (comp == Equator.Comp.DEFAULT) ? null : comp;
    }
@Override public Comparator<? super K> comparator() {
        return (comp == Equator.Comp.DEFAULT) ? null : comp;
    }
@ Override public Comparator < ? super K > comparator ( ) { return ( comp == Equator . Comp . DEFAULT ) ? null : comp ; }
Returns the comparator used to order the keys in this map, or null if it uses
Fn2.DEFAULT_COMPARATOR (for compatibility with java.util.SortedMap).
Returns the comparator used to order the keys in this map or null if it uses Fn2 . DEFAULT_COMPARATOR ( for compatibility with java . util . SortedMap ) .