code: public static String newStringUtf8(byte[] bytes) {
      if (bytes == null) {
        return null;
      }
      return new String(bytes, StandardCharsets.UTF_8);
    }
docs: Constructs a new <code>String</code> by decoding the specified array of bytes using the UTF-8
  charset.
  
  @param bytes The bytes to be decoded into characters
  @return A new <code>String</code> decoded from the specified array of bytes using the UTF-8
  charset, or <code>null</code> if the input byte array was <code>null</code>.
  @throws IllegalStateException Thrown when a {@link UnsupportedEncodingException} is caught,
  which should never happen since the charset is required.
  @since 1.8