@NotNull Collection<CompilerRef.CompilerClassHierarchyElementDef> getDirectInheritors(CompilerRef hierarchyElement)
      throws StorageException {
      Set<CompilerRef.CompilerClassHierarchyElementDef> result = new HashSet<>();
      myIndex.get(JavaCompilerIndices.BACK_HIERARCHY).getData(hierarchyElement).forEach((id, children) -> {
        for (CompilerRef child : children) {
          if (child instanceof CompilerRef.CompilerClassHierarchyElementDef && !(child instanceof CompilerRef.CompilerAnonymousClassDef)) {
            result.add((CompilerRef.CompilerClassHierarchyElementDef)child);
          }
        }
        return true;
      });
      return result;
    }
@NotNull Collection<CompilerRef.CompilerClassHierarchyElementDef> getDirectInheritors(CompilerRef hierarchyElement)