protected @NotNull Set<PsiPackage> getContext() {
    if (myIndex == 0) return myReferenceSet.getInitialContext();
    Set<PsiPackage> psiPackages = new HashSet<>();
    for (ResolveResult resolveResult : myReferenceSet.getReference(myIndex - 1).doMultiResolve()) {
      PsiElement psiElement = resolveResult.getElement();
      if (psiElement instanceof PsiPackage) {
        psiPackages.add((PsiPackage)psiElement);
      }
    }
    return psiPackages;
  }
protected @NotNull Set<PsiPackage> getContext()