question: private Object readResolve ( ) { synchronized ( levels ) { for ( Level level : levels ) { if ( value != level . value ) { continue ; } if ( ! name . equals ( level . name ) ) { continue ; } if ( Objects . equal ( resourceBundleName , level . resourceBundleName ) ) { return level ; } } levels . add ( this ) ; return this ; } }
target:  Serialization helper method to maintain singletons and add any new levels.