@Override
    public long checksum() {
        if (this.checksum == 0) {
            this.checksum = CrcUtil.crc64(AsciiStringUtil.unsafeEncode(toString()));
        }
        return this.checksum;
    }
@Test
    public void testChecksum() {
        PeerId peer = new PeerId("192.168.1.1", 8081, 1);
        long c = peer.checksum();
        assertTrue(c != 0);
        assertEquals(c, peer.checksum());
    }