public void TestPortion()
{
Bottle justABottle = new Bottle("something");
Portion invalidPortion = new Portion("something", 0);
Assert.IsFalse(invalidPortion.IsValid(), "Invalid portion 1");
justABottle.Name = "something";
Portion validPortion = new Portion("something", 2);
Assert.IsTrue(validPortion.IsValid(), "Valid portion 1");
}