public synchronized @Nullable HashedToken getLegacyToken(){
        return tokenList.stream()
                .filter(HashedToken::isLegacy)
                .findFirst()
                .orElse(null);
    }
public synchronized @ Nullable HashedToken getLegacyToken ( ) { return tokenList . stream ( ) . filter ( HashedToken :: isLegacy ) . findFirst ( ) . orElse ( null ) ; }
@return {@code null} iff there is no legacy token in the store, otherwise the legacy token is returned