code: public void writeAscii(long v) {
      if (v == 0) {
        writeByte('0');
        return;
      }
  
      if (v == Long.MIN_VALUE) {
        writeAscii("-9223372036854775808");
        return;
      }
  
      if (v < 0) {
        writeByte('-');
        v = -v; // needs to be positive so we can use this for an array index
      }
  
      writeBackwards(v);
    }
docs: Adapted from okio.Buffer.writeDecimalLong