public Optional<SpiPushExecutor> findPushExecutorSpiImpl(String clientId, Subscriber subscriber) {
        for (SpiPushExecutor each : pushExecutors) {
            if (each.isInterest(clientId, subscriber)) {
                return Optional.of(each);
            }
        }
        return Optional.empty();
    }
@Test
    void testFindPushExecutorSpiImpl() {
        Mockito.when(spiPushExecutor.isInterest(CLIENT_ID, subscriber)).thenReturn(true);
        Optional<SpiPushExecutor> pushExecutorSpiImpl = spiImplPushExecutorHolder.findPushExecutorSpiImpl(CLIENT_ID, subscriber);
        
        assertTrue(pushExecutorSpiImpl.isPresent());
    }