void addClientInitProxy(CacheClientProxy proxy) {
    _initClientProxies.put(proxy.getProxyID(), proxy);
  }
Adds a new {@code CacheClientProxy} to the list of known client proxies

@param proxy The {@code CacheClientProxy} to add
geode-core/src/main/java/org/apache/geode/internal/cache/tier/sockets/CacheClientNotifier.java