template<class EXT_ID, class INT_ID, class HASH_KEY, class COMPARE_KEYS, class ACE_LOCK> class ACE_Hash_Map_Manager_Ex< EXT_ID, INT_ID, HASH_KEY, COMPARE_KEYS, ACE_LOCK > how is the HASH_KEY, COMPARE_KEYS, ACE_LOCK used? when are they called? How to understand it?