public void Add(Actor item, IfcRoleEnum role) { if (!inner.Add(item)) { return; } var create = new Create(schedule.Entity.Model); var rel = rels.FirstOrDefault(); if (rel == null) { rel = create.RelAssignsToActor(r => r.RelatingActor = item.Entity); rels.Add(rel); } rel.RelatedObjects.Add(schedule.Entity); rel.ActingRole = create.ActorRole(r => r.Role = role); }