private static void convertQualifierViaCollectors(PsiReferenceExpression ref,
                                                    Collection<? extends ExpectedTypeInfo> expectedTypes,
                                                    Consumer<? super LookupElement> consumer,
                                                    PsiExpression qualifier,
                                                    @NotNull PsiClass collectors) {
    for (Pair<String, PsiType> pair : suggestCollectors(expectedTypes, qualifier)) {
      if (collectors.findMethodsByName(pair.first, true).length == 0) continue;
      consumer.consume(new CollectLookupElement(pair.first, pair.second, ref));
    }
  }
private static void convertQualifierViaCollectors(PsiReferenceExpression ref,
                                                    Collection<? extends ExpectedTypeInfo> expectedTypes,
                                                    Consumer<? super LookupElement> consumer,
                                                    PsiExpression qualifier,
                                                    @NotNull PsiClass collectors)