public void Update()
{
Organization org = new Organization();
org.Name = DefaultOrgName();
org.BillingRate = 10;
var db = new PostulateDb();
db.Save(org);
int orgId = org.Id;
org.BillingRate = 11;
db.Update(org, r => r.BillingRate);
org = db.Find <Organization>(orgId);
db.DeleteOne <Organization>(orgId);
Assert.IsTrue(org.BillingRate == 11);
}