question: public Whitelist ( Collection < String > patterns , int statusCode ) { if ( patterns == null || patterns . isEmpty ( ) ) { this . patterns = Collections . emptyList ( ) ; } else { ImmutableList . Builder < Pattern > builder = ImmutableList . builder ( ) ; for ( String pattern : patterns ) { builder . add ( Pattern . compile ( pattern ) ) ; } this . patterns = builder . build ( ) ; } this . statusCode = statusCode ; this . enabled = true ; }
target:  Creates a whitelist for the specified patterns, returning the given statusCode when a URL does not match one of the patterns. A null or empty collection will result in an empty whitelist.