Concat enumerables

gistfile1.txt

    [Test]
    public void TEST()
    {
        var results = FirstResults().Concat(GetResults());

        Console.WriteLine("results created");

        Console.WriteLine("get first");
        results.First();
        Console.WriteLine("get last");
        results.Last();
        Console.WriteLine("get all");
        results.ShouldBe(new[] {1, 2, 3, 4});
    }

    private IEnumerable<int> FirstResults()
    {
        Console.WriteLine("yield 1");
        yield return 1;
        Console.WriteLine("yield 2");
        yield return 2;
    }

    private IEnumerable<int> GetResults()
    {
        Console.WriteLine("yield 3");
        yield return 3;
        Console.WriteLine("yield 4");
        yield return 4;
    }

/*
results created
get first
yield 1
get last
yield 1
yield 2
yield 3
yield 4
get all
yield 1
yield 2
yield 3
yield 4
*/