public async Task Container_AddContent_AllowedElement_Works(Fb2Container node) { node.Should().NotBeNull(); var allowedElementName = node.AllowedElements.First(); var firstAllowedNode = Fb2NodeFactory.GetNodeByName(allowedElementName); node.AddContent(firstAllowedNode); node.Content.Should().NotBeEmpty().And.Subject.Should().HaveCount(1); ClearContainerContent(node); // params Fb2Node[] nodes node.AddContent(firstAllowedNode, firstAllowedNode); // lol node.Content.Should().NotBeEmpty().And.Subject.Should().HaveCount(2); ClearContainerContent(node); node.AddContent(() => firstAllowedNode); // Func<Fb2Node> node.Content.Should().NotBeEmpty().And.Subject.Should().HaveCount(1); ClearContainerContent(node); node.AddContent(new List <Fb2Node> { firstAllowedNode }); // IEnumerable<Fb2Node> node.Content.Should().NotBeEmpty().And.Subject.Should().HaveCount(1); ClearContainerContent(node); // async node provider await node.AddContentAsync(async() => await Task.FromResult(firstAllowedNode)); node.Content.Should().NotBeEmpty().And.Subject.Should().HaveCount(1); ClearContainerContent(node); //string name node.AddContent(node.AllowedElements.First()); node.Content.Should().HaveCount(1); }