public void UpdatePerson(Person person)
 {
     using (var ctx = new ExampleDbContext())
     {
         ctx.People.Attach(person);
         ctx.Entry(person).State = EntityState.Modified;
         ctx.SaveChanges();
     }
 }
 public virtual void Update(T entity)
 {
     dbSet.Attach(entity);
     dataContext.Entry(entity).State = EntityState.Modified;
 }