src/main/java/org/organicdesign/fp/StaticImports.java
public static <T> ImSortedSet<T> sortedSet(Comparator<? super T> comp, Iterable<T> elements) {
        return Xform.of(elements).toImSortedSet(comp);
    }
public static <T> ImSortedSet<T> sortedSet(Comparator<? super T> comp, Iterable<T> elements) {
        return Xform.of(elements).toImSortedSet(comp);
    }
Returns a new PersistentTreeSet of the given comparator and items.

@param comp A comparator that defines the sort order of elements in the new set.  This
becomes part of the set (it's not for pre-sorting).
@param elements items to go into the set.  In the case of duplicates, later elements overwrite
earlier ones.
@return a new PersistentTreeSet of the specified comparator and the given elements