public Duration getStartSlack ( ) { Duration startSlack = ( Duration ) getCachedValue ( TaskField . START_SLACK ) ; if ( startSlack == null ) { Duration duration = getDuration ( ) ; if ( duration != null ) { startSlack = DateHelper . getVariance ( this , getEarlyStart ( ) , getLateStart ( ) , duration . getUnits ( ) ) ; set ( TaskField . START_SLACK , startSlack ) ; } } return ( startSlack ) ; }
Retrieve the start slack .