Entity Framework CTP4 Code First: Mapping protected properties

I would like to use a lazy-loading collection on a model, but I want Add/Remove functionality to be done through separate methods. So something like this:

class Model
{
  protected virtual ICollection<Something> _开发者_StackOverflow社区somethings { get; set; }

  public IEnumerable<Something> Somethings 
  { 
    get { return _somethings; } 
  }

  public void AddSomething(Something thingToAdd)
  {
    /*  logic */
    _somethings.Add(thingToAdd);
  }
}

I can't figure out how to configure the mapping for this. I looked into using a configuration class: EntityConfiguration. But since the property is protected I can't figure out how to set a configuration on it. Is there any way to accomplish what I'm trying to do here?

You can use readonly static Expression for access to protected property like this

protected virtual ICollection<Something> _somesing { get; set; }
public static readonly Expression<Func<Model, ICollection<Something>>> Expression = p => p._something;

public IReadOnlyCollection<Something> Something
{
     return _sumething.AsReadOnly();
}

And use it in OnModelCreating method in DbContext class for mapping protected property

protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
    modelBuilder.Entity<Model>().HasMany<Something>(Model.Expression);
}

I suppose if you declare the configuration class (inheriting EntityConfiguration) inside your Model class, it could work. It's not a nice solution, since subclassing is generally discouraged, but it's the only thing I can think of.

Ive heard this only can be done using EDMX file way.. not code first.