public void When_Passing_Null_Parameters_Then_Exceptions_Are_Thrown()
{
// ARRANGE
InitializeFakeObjects();
// ACTS & ASSERTS
Assert.ThrowsAsync <ArgumentNullException>(() => _tokenClient.ExecuteAsync(string.Empty));
Assert.ThrowsAsync <ArgumentNullException>(() => _tokenClient.ResolveAsync(string.Empty));
}