@NotNull
    private MutablePackageFragmentDescriptor getOrCreatePackageFragmentForFile(
        @NotNull JetFile file) {
      JetPackageDirective packageDirective = file.getPackageDirective();
      assert packageDirective != null : "scripts are not supported";

      MutablePackageFragmentDescriptor fragment =
          packageFragmentProvider.getOrCreateFragment(packageDirective.getFqName());

      ModuleDescriptor module = packageFragmentProvider.getModule();
      DescriptorResolver.resolvePackageHeader(
          packageDirective, module, TypeHierarchyResolver.this.trace);

      trace.record(BindingContext.FILE_TO_PACKAGE_FRAGMENT, file, fragment);

      // Register files corresponding to this package
      // The trace currently does not support bi-di multimaps that would handle this task nicer
      FqName fqName = fragment.getFqName();
      Collection<JetFile> files = trace.get(PACKAGE_TO_FILES, fqName);
      if (files == null) {
        files = Sets.newIdentityHashSet();
      }
      files.add(file);
      trace.record(BindingContext.PACKAGE_TO_FILES, fqName, files);
      return fragment;
    }
 @NotNull
 @Override
 public FqName getContainingPackageFqName() {
   PsiFile file = element.getContainingFile();
   if (file instanceof JetFile) {
     JetFile jetFile = (JetFile) file;
     JetPackageDirective directive = jetFile.getPackageDirective();
     return directive != null ? directive.getFqName() : FqName.ROOT;
   }
   throw new IllegalArgumentException("Not in a JetFile: " + element);
 }