private static void AssertCompositeMapping(ClassMapping mapping)
{
Assert.AreEqual(3, mapping.IdDataColsByObjAttrs.Count, "Should be three id columns.");
Assert.AreEqual(2, mapping.NonIdDataColsByObjAttrs.Count, "Should be 2 property columns.");
Assert.AreEqual("IDCol1", mapping.IdDataColsByObjAttrs["ID1"], "Wrong column mapped for ID 1.");
Assert.AreEqual("IDCol2", mapping.IdDataColsByObjAttrs["ID2"], "Wrong column mapped for ID 2.");
Assert.AreEqual("IDCol3", mapping.IdDataColsByObjAttrs["ID3"], "Wrong column mapped for ID 3.");
Assert.AreEqual("PropCol1", mapping.NonIdDataColsByObjAttrs["Prop1"], "Wrong column mapped for Property 1.");
Assert.AreEqual("PropCol2", mapping.NonIdDataColsByObjAttrs["Prop2"], "Wrong column mapped for Property 2.");
}