public async Task GetAsync_should_not_be_implemented()
{
var sut = new KeyStore <Key>(Task.FromResult(new HttpClient()), new NullLogger <KeyStore <Key> >());
await Assert.ThrowsAsync <NotImplementedException>(() => sut.GetAsync(null));
await Assert.ThrowsAsync <NotImplementedException>(() => sut.GetAsync(null, null));
}