public void AddOneListIntoAnotherTest()
{
var list = new List <int> {
1, 2, 3, 4, 5
};
var other = new List <int> {
6, 7, 8, 9, 10
};
var target = Colls.AddRange(list, other).ToList();
list.Count.ShouldBe(5);
target.Count.ShouldBe(10);
other.Count.ShouldBe(5);
target[0].ShouldBe(1);
target[1].ShouldBe(2);
target[2].ShouldBe(3);
target[3].ShouldBe(4);
target[4].ShouldBe(5);
target[5].ShouldBe(6);
target[6].ShouldBe(7);
target[7].ShouldBe(8);
target[8].ShouldBe(9);
target[9].ShouldBe(10);
}