code: public AESCipher setKey(String key, byte[] iv)
      {
          byte[] key2 = Utils.getBytesUTF8(key);
  
          return setKey(key2, iv);
      }
docs: Set cipher initialization parameters.
  
  @param key
  Secret key. The value is converted to a byte array
  by {@code key.getBytes("UTF-8")} and used as the
  first argument of {@link #setKey(byte[], byte[])}.
  If {@code null} is given, {@code null} is passed
  to {@link #setKey(byte[], byte[])}.
  
  @param iv
  Initial vector. The value is pass to {@link
  #setKey(byte[], byte[])} as the second argument
  as is.
  
  @return
  {@code this} object.
  
  @since 1.2