@VisibleForTesting
    static final String extractClientIpFromXForwardedFor(String xForwardedFor) {
        return xForwardedFor.split(",")[0];
    }
@Test
    void extractsClientIpFromXForwardedFor() {
        final String ip1 = "hi";
        final String ip2 = "hey";
        assertEquals(ip1, StatsManager.extractClientIpFromXForwardedFor(ip1));
        assertEquals(ip1, StatsManager.extractClientIpFromXForwardedFor(String.format("%s,%s", ip1, ip2)));
        assertEquals(ip1, StatsManager.extractClientIpFromXForwardedFor(String.format("%s, %s", ip1, ip2)));
    }