question: private void check ( ) { if ( descs . length == 0 ) { throw new IllegalArgumentException ( "must have at least one descriptor" ) ; } for ( int i = 0 ; i < descs . length ; i ++ ) { MethodDesc desc = descs [ i ] ; String dname = desc . name ; if ( dname == null ) { if ( i < descs . length - 1 ) { throw new IllegalArgumentException ( "default descriptor must be last" ) ; } } else if ( dname . charAt ( 0 ) == '*' ) { int dlen = dname . length ( ) + 1 ; for ( int j = 0 ; j < i ; j ++ ) { MethodDesc prev = descs [ j ] ; String pname = prev . name ; if ( pname . charAt ( 0 ) == '*' && pname . regionMatches ( 1 , dname , dlen - pname . length ( ) , pname . length ( ) - 1 ) ) { check ( prev , desc ) ; } } } else if ( dname . charAt ( dname . length ( ) - 1 ) == '*' ) { for ( int j = 0 ; j < i ; j ++ ) { MethodDesc prev = descs [ j ] ; String pname = prev . name ; int plen = pname . length ( ) - 1 ; if ( pname . charAt ( plen ) == '*' && pname . regionMatches ( 0 , dname , 0 , plen ) ) { check ( prev , desc ) ; } } } else { for ( int j = 0 ; j < i ; j ++ ) { MethodDesc prev = descs [ j ] ; String pname = prev . name ; int plen = pname . length ( ) - 1 ; if ( pname . charAt ( 0 ) == '*' ) { if ( dname . regionMatches ( dname . length ( ) - plen , pname , 1 , plen ) ) { check ( prev , desc ) ; } } else if ( pname . charAt ( plen ) == '*' ) { if ( dname . regionMatches ( 0 , pname , 0 , plen ) ) { check ( prev , desc ) ; } } else { if ( pname . equals ( dname ) ) { check ( prev , desc ) ; } } } } } }
target:  Throws IllegalArgumentException if the descriptors array is empty, or if any descriptor is preceded by another descriptor that matches at least the same methods. Throws NullPointerException if the array or any element is null.