code: public static <K, V> TreeMultimap<K, V> create(
        Comparator<? super K> keyComparator, Comparator<? super V> valueComparator) {
      return new TreeMultimap<K, V>(checkNotNull(keyComparator), checkNotNull(valueComparator));
    }
docs: Creates an empty {@code TreeMultimap} instance using explicit comparators.
  Neither comparator may be null; use {@link Ordering#natural()} to specify
  natural order.
  
  @param keyComparator the comparator that determines the key ordering
  @param valueComparator the comparator that determines the value ordering