question: public final static byte [ ] successor ( final byte [ ] key ) { final int keylen = key . length ; final byte [ ] tmp = new byte [ keylen + 1 ] ; System . arraycopy ( key , 0 , tmp , 0 , keylen ) ; return tmp ; }
target:  Computes the successor of a variable length byte array by appending a unsigned zero(0) byte to the end of the array.