progress condition : blocking concode_field_sep CRWWPLock crwwpLock concode_elem_sep TreeSet<E> treeSet concode_field_sep boolean contains concode_elem_sep boolean addAll concode_elem_sep boolean remove
boolean function ( E arg0 ) { crwwpLock . writeLock ( ) . lock ( ) ; try { return treeSet . add ( arg0 ) ; } finally { crwwpLock . writeLock ( ) . unlock ( ) ; } }