question: public static String retrieveDisplayName ( String id , boolean daylight , int style , Locale locale ) { String [ ] names = retrieveDisplayNamesImpl ( id , locale ) ; if ( Objects . nonNull ( names ) ) { return names [ ( daylight ? 4 : 2 ) - style ] ; } else { return null ; } }
target:  Retrieves a standard or daylight-saving time name for the given time zone ID.