@Override
    public boolean checkConnection(final Endpoint endpoint, final boolean createIfAbsent) {
        final RpcClient rc = this.rpcClient;
        if (rc == null) {
            throw new IllegalStateException("Client service is uninitialized.");
        }
        return rc.checkConnection(endpoint, createIfAbsent);
    }
Abstract RPC client service based.
@author boyan (boyan@alibaba-inc.com)
@author jiachun.fjc
jraft-core/src/main/java/com/alipay/sofa/jraft/rpc/impl/AbstractClientService.java