private long inc(long value) {
    long val = value + 1;
    val = val == MAXIMUM_KEY ? 0 : val;
    return val;
  }
returns true if key a is before key b. This test handles keys that have wrapped around
geode-core/src/main/java/org/apache/geode/internal/cache/wan/serial/SerialGatewaySenderQueue.java