question: public long calculateEndTime ( ) { if ( endTime == 0 ) { return System . currentTimeMillis ( ) ; } else if ( endTime < 0 ) { return System . currentTimeMillis ( ) - endTime ; } return endTime ; }
target:  This method returns an end time based on the configured value. If end time is less or equal to 0, then its value will be deducted from the current time.