* cds_lfht_add_unique (success), cds_lfht_add_replace, cds_lfht_del.
*
* When cds_lfht_add_unique succeeds (returns the node passed as
* cds_lfht_add_unique (success), cds_lfht_add_replace, cds_lfht_del.
*
* When cds_lfht_add_unique succeeds (returns the node passed as