@Override
    public long checksum() {
        if (this.checksum == 0) {
            this.checksum = CrcUtil.crc64(AsciiStringUtil.unsafeEncode(toString()));
        }
        return this.checksum;
    }
Node's local priority value, if node don't support priority election, this value is -1.
jraft-core/src/main/java/com/alipay/sofa/jraft/entity/PeerId.java