public void TestDensityCalculation() { Assert.AreEqual(-4.99d, (Density.FromGramPerCubicMeter(10d) - Density.FromGramPerLitre(5d)).GramPerLitre, DoubleDelta); Assert.AreEqual(5.01d, (Density.FromGramPerCubicMeter(10d) + Density.FromGramPerLitre(5d)).GramPerLitre, DoubleDelta); }