private static void handleOneByte(byte byte1, char[] resultArr, int resultPos) {
            resultArr[resultPos] = (char) byte1;
        }
Returns whether this is a three-byte codepoint with the form '110XXXXX'.
jraft-core/src/main/java/com/alipay/sofa/jraft/util/internal/UnsafeUtf8Util.java