private static byte[] withCorrectBlockSize(final byte[] key){
  if (key.length != CcAes.BLOCK) {
    throw new IllegalArgumentException(String.format("the length of the AES key must be exactly %d bytes",CcAes.BLOCK));
  }
  return key;
}

private static byte [ ] withCorrectBlockSize ( final byte [ ] key ) { if ( key . length != CcAes . BLOCK ) { throw new IllegalArgumentException ( String . format ( "the length of the AES key must be exactly %d bytes" , CcAes . BLOCK ) ) ; } return key ; }
check the block size of the key .
