@Test
    public void testRemoveSelector() {
        when(selectorData.getId()).thenReturn(null);
        grpcPluginDataHandler.removeSelector(selectorData);
        when(selectorData.getId()).thenReturn("selectorId");
        grpcPluginDataHandler.removeSelector(selectorData);
        final List<ShenyuServiceInstance> shenyuServiceInstances = ApplicationConfigCache.getInstance().get(selectorData.getId()).getShenyuServiceInstances();
        assertTrue(CollectionUtils.isEmpty(shenyuServiceInstances), "shenyuServiceInstances mast is empty");
    }
The Test Case For {@link GrpcPluginDataHandler}.
shenyu-plugin/shenyu-plugin-proxy/shenyu-plugin-rpc/shenyu-plugin-grpc/src/test/java/org/apache/shenyu/plugin/grpc/handler/GrpcPluginDataHandlerTest.java