public CacheClientProxy getClientProxy(ClientProxyMembershipID membershipID,
      boolean proxyInInitMode) {
    CacheClientProxy proxy = getClientProxy(membershipID);
    if (proxyInInitMode && proxy == null) {
      proxy = _initClientProxies.get(membershipID);
    }
    return proxy;
  }
Returns the CacheClientProxy associated to the membershipID. This looks at both proxies that
are initialized and those that are still in initialization mode.
geode-core/src/main/java/org/apache/geode/internal/cache/tier/sockets/CacheClientNotifier.java