code: public static byte[] decodeFromString(String src) {
  		if (src == null) {
  			return null;
  		}
  		if (src.length() == 0) {
  			return new byte[0];
  		}
  		byte[] result;
  		try {
  			result = delegate.decode(src.getBytes(DEFAULT_CHARSET.displayName()));
  		} catch (UnsupportedEncodingException e) {
  			// should not happen, UTF-8 is always supported
  			throw new IllegalStateException(e);
  		}
  		return result;
  	}
docs: Base64-decode the given byte array from an UTF-8 String.
  @param src the encoded UTF-8 String (may be {@code null})
  @return the original byte array (or {@code null} if the input was {@code null})
  @since 2.0