public void Configurer_Test()
{
var configurer = new TestConfigurer();
ICalculator calculator = new CalculatorFactory(configurer).createInstance();
double result = calculator.Compute("~3.3");
Assert.AreEqual(3d, result);
result = calculator.Compute("~3.3+2.8");
Assert.AreEqual(5.8d, result);
result = calculator.Compute("3.3+2.8~");
Assert.AreEqual(4.1d, result);
result = calculator.Compute("3.3+2.8~*2");
Assert.AreEqual(4.9d, result, 0.00001);
}