@Override
      public boolean done() {
        int primaryPort = pool.getPrimaryPort();
        if (primaryPort == -1) {
          return false;
        }
        // we have a primary
        VM currentPrimary = getServerVM(primaryPort);
        return currentPrimary != oldPrimary;
      }
Return the current primary waiting for a primary to exist and for it not to be the oldPrimary
(if oldPrimary is NOT null).

@since GemFire 5.7
geode-core/src/distributedTest/java/org/apache/geode/internal/cache/tier/sockets/HAInterestTestCase.java