question: public static FlickrPhoto matchURL ( String url , String text ) { Matcher m = GROUPING_PATTERN . matcher ( url ) ; if ( m . matches ( ) ) { return new FlickrPhoto ( m . group ( 1 ) , null , m . group ( 2 ) , m . group ( 3 ) , text ) ; } m = URL_PATTERN . matcher ( url ) ; if ( m . matches ( ) ) { return new FlickrPhoto ( m . group ( 1 ) , m . group ( 2 ) , null , null , text ) ; } else { return null ; } }
target:  Returns a FlickrPhoto object if the given url is to a photo or Flickr user.