public void TestAggregateExceptions()
{
int[] array = null;
Func <int, int, int> myFunc = (x, z) => x * z;
Assert.Throws <ArgumentNullException>(() => LinqFunctions.Aggregate(array, 5, (a, b) => myFunc(a, b)));
}
public void TestAggregateWhenValid()
{
int[] array = { 1, 2, 4, 5 };
Func <int, int, int> myFunc = (x, z) => x * z;
var result = LinqFunctions.Aggregate(array, 5, (a, b) => myFunc(a, b));
Assert.Equal(200, result);
}