added check to avoid handlername conflict

plugin/manager.go

@@ -195,7 +195,10 @@ func (m *manager) Register(syncer syncertypes.Base) error {
 	defer m.m.Unlock()
 
 	if int, ok := syncer.(Interceptor); ok {
-		m.interceptors[int.Name()] = int.Handler()
+		if _, ok := m.interceptors[int.Config().HandlerName]; ok {
+			return fmt.Errorf("could not add the interceptor %s because the handler name %s is already in use", int.Name(), int.Config().HandlerName)
+		}
+		m.interceptors[int.Config().HandlerName] = int.Handler()
 	} else {
 		m.syncers = append(m.syncers, syncer)
 	}