@Test
public void testExistsThrottlingWhenShardFound() {

    throttleOperation(transactionProxy -> {
        doReturn(incompleteFuture()).when(mockActorContext).executeOperationAsync(
                any(ActorSelection.class), eqDataExists());
        transactionProxy.exists(TestModel.TEST_PATH);
        transactionProxy.exists(TestModel.TEST_PATH);
    });
}