code: public static int utf8EncodedLength(@Nullable CharSequence sequence) {
  		if (StringUtils.isEmpty(sequence)) {
  			return 0;
  		}
  		return Utf8.encodedLength(sequence);
  	}
docs: 计算字符串被UTF8编码后的字节数 via guava
  
  @see Utf8#encodedLength(CharSequence)