@NotNull
 public final List<CollectionChildDescriptionImpl> getCollectionChildrenDescriptions() {
   checkInitialized();
   return myCollections.getDescriptions();
 }
 @NotNull
 public List<AttributeChildDescriptionImpl> getAttributeChildrenDescriptions() {
   checkInitialized();
   return myAttributes.getDescriptions();
 }
 @NotNull
 public final List<FixedChildDescriptionImpl> getFixedChildrenDescriptions() {
   checkInitialized();
   return myFixeds.getDescriptions();
 }