android/guava/src/com/google/common/collect/ImmutableSortedMultiset.java
public static <E> Builder<E> orderedBy(Comparator<E> comparator) {
    return new Builder<E>(comparator);
  }
public static <E> Builder<E> orderedBy(Comparator<E> comparator) {
    return new Builder<E>(comparator);
  }
Returns a builder that creates immutable sorted multisets with an explicit comparator. If the
comparator has a more general type than the set being generated, such as creating a {@code
SortedMultiset<Integer>} with a {@code Comparator<Number>}, use the {@link Builder} constructor
instead.

@throws NullPointerException if {@code comparator} is null