public void TestPKKey <T>(Expression <Func <MyDataKeys, T> > pkGetter, Action <MyDataKeys, T> pkSetter, T key)
{
var db = new DbInstance("DbKeys");
db.Map <MyDataKeys>().Key(pkGetter);
db.Initialize();
var getter = pkGetter.Compile();
var obj1 = new MyDataKeys();
pkSetter(obj1, key);
db.Save(obj1);
var obj2 = db.LoadByKey <MyDataKeys>(key);
Assert.AreEqual(getter(obj1), getter(obj2));
db.Purge();
}