private @NotNull Iterable<LookupElement> liftShorterElements(@NotNull Iterable<? extends LookupElement> source,
                                                               @Nullable Set<? super LookupElement> lifted,
                                                               @NotNull ProcessingContext context) {
    Set<LookupElement> srcSet = new ReferenceOpenHashSet<>(source instanceof Collection ? ((Collection<?>)source).size() : myCount);
    ContainerUtil.addAll(srcSet, source);
    if (srcSet.size() < 2) {
      return myNext.classify(source, context);
    }
    return new LiftingIterable(srcSet, context, source, lifted);
  }
private @NotNull Iterable<LookupElement> liftShorterElements(@NotNull Iterable<? extends LookupElement> source,
                                                               @Nullable Set<? super LookupElement> lifted,
                                                               @NotNull ProcessingContext context)