public Set<PsiFile> getDependentFilesInPackage(PsiPackage firstPack, PsiPackage middlePack, PsiPackage lastPack) {
    Set<PsiFile> result = new HashSet<>();
    final Map<PsiPackage, Set<PsiFile>> forwardMap = myFilesInDependentPackages.get(firstPack);
    if (forwardMap != null && forwardMap.get(middlePack) != null){
      result.addAll(forwardMap.get(middlePack));
    }
    final Map<PsiPackage, Set<PsiFile>> backwardMap = myBackwardFilesInDependentPackages.get(lastPack);
    if (backwardMap != null && backwardMap.get(middlePack) != null){
      result.addAll(backwardMap.get(middlePack));
    }
    return result;
  }
public Set<PsiFile> getDependentFilesInPackage(PsiPackage firstPack, PsiPackage middlePack, PsiPackage lastPack)