code: public void start() {
  		synchronized (lock) {
  			Preconditions.checkState(!isShutdown, "The KvStateService has already been shut down.");
  
  			LOG.info("Starting the kvState service and its components.");
  
  			if (kvStateServer != null) {
  				try {
  					kvStateServer.start();
  				} catch (Throwable ie) {
  					kvStateServer.shutdown();
  					kvStateServer = null;
  					LOG.error("Failed to start the Queryable State Data Server.", ie);
  				}
  			}
  
  			if (kvStateClientProxy != null) {
  				try {
  					kvStateClientProxy.start();
  				} catch (Throwable ie) {
  					kvStateClientProxy.shutdown();
  					kvStateClientProxy = null;
  					LOG.error("Failed to start the Queryable State Client Proxy.", ie);
  				}
  			}
  		}
  	}
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