private void AssertEvent(ObjectModifiedArgs oma, EventListener<ObjectModifiedArgs> el, int evn)
        { 
           // int evc = el.EventCount;
            
            Assert.IsNotNull(oma);
            Assert.AreEqual(evn,el.EventCount);

            ObjectModifiedArgs ev = null;

            if (evn == 1)
            {
                ev = el.GetDeplieEvent();
            }
            else
            {
                var po = el.GetDeplieEvents().Where(o => o.AttributeName == oma.AttributeName).ToList();
                Assert.AreEqual(po.Count, 1);
                ev = po.First();
            }            
                
            Assert.IsNotNull(ev);
           
            Assert.AreEqual(ev.AttributeName, oma.AttributeName);
            Assert.AreEqual(ev.OldAttributeValue, oma.OldAttributeValue);
            Assert.AreEqual(ev.NewAttributeValue, oma.NewAttributeValue);
        }