private @Nullable Set<VirtualFile> getReferentFileIdsViaImplicitToString(@NotNull PsiElement element) {
    return getReferentFiles(element, false, (ref, elementPlace) -> myReader.findFileIdsWithImplicitToString(ref));
  }
private @Nullable Set<VirtualFile> getReferentFileIdsViaImplicitToString(@NotNull PsiElement element)