public final void writeRaw(byte b) {
        int off = this.off;
        grow1(off)[off] = b;
        this.off = off + 1;
    }
A faster alternative that is functionally equivalent to Long.expand(i, 0x0F0F_0F0F_0F0F_0F0FL)
core/src/main/java/com/alibaba/fastjson2/JSONWriterUTF8.java