public async Task EnsuresNonNullArguments()
{
var client = new ObservableFollowersClient(Substitute.For<IGitHubClient>());
await Assert.ThrowsAsync<ArgumentNullException>(() => client.Unfollow(null).ToTask());
await Assert.ThrowsAsync<ArgumentException>(() => client.Unfollow("").ToTask());
}
public void UnfollowFromClientUserFollowers()
{
var githubClient = Substitute.For<IGitHubClient>();
var client = new ObservableFollowersClient(githubClient);
client.Unfollow("alfhenrik");
githubClient.User.Followers.Received()
.Unfollow("alfhenrik");
}