public Class<?> getServiceInterface() {
      return this.serviceInterface;
    }
Datastructure for passing a {@link BlockingService} and its associated class of protobuf
service interface. For example, a server that fielded what is defined in the client protobuf
service would pass in an implementation of the client blocking service and then its
ClientService.BlockingInterface.class. Used checking connection setup.
hbase-server/src/main/java/org/apache/hadoop/hbase/ipc/RpcServer.java