private static String doUnescape(byte[] value) {
        final ByteBuffer buf = ByteBuffer.allocate(value.length);
        for (int i = 0; i < value.length;) {
            if (value[i] == '%' && i + 2 < value.length) {
                try {
                    buf.put((byte) Integer
                            .parseInt(new String(value, i + 1, 2, StandardCharsets.UTF_8), 16));
                    i += 3;
                    continue;
                } catch (NumberFormatException e) {
                    // ignore, fall through, just push the bytes.
                }
            }
            buf.put(value[i]);
            i += 1;
        }
        return new String(buf.array(), 0, buf.position(), StandardCharsets.UTF_8);
    }
Unescape the provided ascii to a unicode {@link String}.
grpc-protocol/src/main/java/com/linecorp/armeria/common/grpc/protocol/StatusMessageEscaper.java