public async Task <double> Apply(double amount, string postalCode)
{
// Logic is as simple as possible because the goal is to explore the testing options, not the complexity of the problem.
var response = await _locationClient.GetDetails(postalCode);
if (response.Province == "QC")
{
return(amount * QuebecTaxRate);
}
else
{
return(amount * RestOfCanadaTaxRate);
}
}