question: public static < A > A [ ] append ( final A [ ] a , final A [ ] b ) { final int alen = a . length ; final int blen = b . length ; final A [ ] res = Arrays . copyOf ( a , alen + blen ) ; System . arraycopy ( b , 0 , res , alen , blen ) ; return res ; }
target:  Append two arrays creating a new array for the result.