public Object readFrom(ResultSet rs, CollectionPersister persister, CollectionAliases descriptor, Object owner)
   throws HibernateException, SQLException {
      Object element = persister.readElement( rs, owner, descriptor.getSuffixedElementAliases(), getSession() );
      Object index = persister.readIndex( rs, descriptor.getSuffixedIndexAliases(), getSession() );
      if ( element!=null ) map.put(index, element);
      return element;
   }