question: @ ParametersAreNonnullByDefault public static List < Size > filterBlackListedSizes ( List < Size > sizes , String blacklistString ) { String [ ] blacklistStringArray = blacklistString . split ( "," ) ; if ( blacklistStringArray . length == 0 ) { return sizes ; } Set < String > blacklistedSizes = new HashSet ( Lists . newArrayList ( blacklistStringArray ) ) ; List < Size > newSizeList = new ArrayList < > ( ) ; for ( Size size : sizes ) { if ( ! isBlackListed ( size , blacklistedSizes ) ) { newSizeList . add ( size ) ; } } return newSizeList ; }
target:  Takes selected sizes and a list of blacklisted sizes. All the blacklistes sizes will be removed from the 'sizes' list.