public <T> Mono<CosmosItemResponse<T>> createItem(
            final T item, final PartitionKey partitionKey, final CosmosItemRequestOptions itemRequestOptions) {
        CosmosDbUtils.validateIfParameterIsNotEmpty(item, PARAM_ITEM);
        CosmosDbUtils.validateIfParameterIsNotEmpty(partitionKey, PARAM_PARTITION_KEY);

        return applyToContainer(container -> container.createItem(item, partitionKey, itemRequestOptions));
    }
@Test
    void testCreateItem() {
        final CosmosDbContainerOperations operations
                = new CosmosDbContainerOperations(Mono.just(mock(CosmosAsyncContainer.class)));

        CosmosDbTestUtils.assertIllegalArgumentException(() -> operations.createItem(null, null, null));
        CosmosDbTestUtils.assertIllegalArgumentException(() -> operations.createItem("", null, null));
        CosmosDbTestUtils.assertIllegalArgumentException(() -> operations.createItem("tes", null, null));
    }