Add unit to the modules  
 dubbo-rpc/dubbo-rpc-hessian
   dubbo-rpc/dubbo-rpc-http
   dubbo-rpc/dubbo-rpc-injvm
*/
package org.apache.dubbo.rpc.protocol.injvm;
import org.apache.dubbo.common.Constants;
import org.apache.dubbo.common.URL;
import org.apache.dubbo.common.extension.ExtensionLoader;
import org.apache.dubbo.common.utils.UrlUtils;
import org.apache.dubbo.rpc.Exporter;
import org.apache.dubbo.rpc.Invoker;
import org.apache.dubbo.rpc.Protocol;
import org.apache.dubbo.rpc.RpcException;
import org.apache.dubbo.rpc.protocol.AbstractProtocol;
import org.apache.dubbo.rpc.support.ProtocolUtils;
import java.util.Map;
/**
 * InjvmProtocol
 */
public class InjvmProtocol extends AbstractProtocol implements Protocol {
    public static final String NAME = Constants.LOCAL_PROTOCOL;
    public static final int DEFAULT_PORT = 0;
    private static InjvmProtocol INSTANCE;
    public InjvmProtocol() {
        INSTANCE = this;
    }
    public static InjvmProtocol getInjvmProtocol() {
        if (INSTANCE == null) {
            ExtensionLoader.getExtensionLoader(Protocol.class).getExtension(InjvmProtocol.NAME); 
        }
        return INSTANCE;
    }
    static Exporter<?> getExporter(Map<String, Exporter<?>> map, URL key) {