public void MapTest()
{
// Given
var a = new[] { 1, 2, 3, 4, 5, 6, 7, 8, 9 };
// When
var b = a.Map(x => x.ToString());
var c = a.Map(x => System.Math.Sqrt(x));
// Then
Assert.AreEqual(b.Length, a.Length);
Assert.AreEqual(c.Length, a.Length);
Assert.AreEqual("1", b[0]);
Assert.AreEqual(3, c[c.Length - 1]);
}