I’m using MVVM with WAF framework. WAF Framework contains a class called EntityCollection: public sealed class EntityCollection<TEntity> : RelatedEnd, ICollection<TEntity>, IEnumerable<TEntity>, IEnumerable, IListSource where TEntity : class { public EntityCollection(); public int Count { get; } public bool IsReadOnly { get; } public void Add(TEntity entity); public void Attach(IEnumerable<TEntity> entities);...