question: private int typeDepth ( Class < ? > match , Class < ? > actual ) { if ( actual == null ) { return Integer . MAX_VALUE / 2 ; } if ( match . equals ( Object . class ) ) { return Integer . MAX_VALUE / 4 ; } if ( match . equals ( actual ) ) { return 0 ; } int cost = 1 + typeDepth ( match , actual . getSuperclass ( ) ) ; for ( Class < ? > iface : actual . getInterfaces ( ) ) { cost = Math . min ( cost , 1 + typeDepth ( match , iface ) ) ; } return cost ; }
target:  count of how closely the source matches the target.