question: public void reserveCapacity ( int additionalCapacity ) throws InterruptedException , NoCapacityAvailableException { Collection < Ticket > tickets = mParentPool . acquire ( additionalCapacity ) ; mLock . lock ( ) ; try { mCapacity += additionalCapacity ; for ( Ticket ticket : tickets ) { mParentTickets . add ( ticket ) ; } releaseWaitersOnTicketAvailability ( ) ; } finally { mLock . unlock ( ) ; } updateCurrentTicketCount ( ) ; }
target:  Reserves tickets from the parent pool.