public void DoSomething_WithCertainParameters_ShouldDoSomething()
{
_matchService
.Expect(x => x.GetMatches(Arg<string>.Is.Anything))
.Return(new []{new Match()});
_sut.DoSomething();
_matchService.AssertWasCalled(x => x.GetMatches(Arg<string>.Is.Anything);
}