private void Test(string op, int a, int b, int c)
{
var operation = OperationFactory <RealNumber> .Instance.GetOperation(op);
var r0 = new RealNumber(a);
var r1 = new RealNumber(b);
var r2 = new RealNumber(c);
var r3 = operation.Operate(r1, r2);
Assert.IsTrue(RealNumber.IsEquals(r0, r3));
}