### ReferenceConfig#init , at line 307
change : prifix -> prefix
<img width="746" alt="1" src="https://user-images.githubusercontent.com/6971152/35309902-a22d3ed2-00e9-11e8-9928-e394b9e3d632.png">

### by the way,  ReferenceConfig#setInterface , at line 476
it's no need to cast null to String
<img width="903" alt="2" src="https://user-images.githubusercontent.com/6971152/35309908-b09e4a92-00e9-11e8-9725-8e6ff8071370.png">

import com.alibaba.dubbo.config.support.Parameter;
import com.alibaba.dubbo.rpc.Invoker;
import com.alibaba.dubbo.rpc.Protocol;
import com.alibaba.dubbo.rpc.ProxyFactory;
import com.alibaba.dubbo.rpc.StaticContext;
import com.alibaba.dubbo.rpc.cluster.Cluster;
import com.alibaba.dubbo.rpc.cluster.directory.StaticDirectory;
import com.alibaba.dubbo.rpc.cluster.support.AvailableCluster;
import com.alibaba.dubbo.rpc.cluster.support.ClusterUtils;
import com.alibaba.dubbo.rpc.protocol.injvm.InjvmProtocol;
import com.alibaba.dubbo.rpc.service.GenericService;
import com.alibaba.dubbo.rpc.support.ProtocolUtils;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Properties;
import static com.alibaba.dubbo.common.utils.NetUtils.isInvalidLocalHost;
/**
 * ReferenceConfig
 *
 * @export
 */
public class ReferenceConfig<T> extends AbstractReferenceConfig {