Is it possible to add a UnMap method on ClassMap?

[alandecastros]

I want to extend a ClassMap and create a new one based on it.
I think this would be achievable by creating a UnMap method that will manipulate the provider.

Example:

public class NoCascadesHomeClassMap : ClassMap<Home>
{
    NoCascadesHomeClassMap()
    {
        HasMany(x => x.Doors);
    }
}

public class FullHomeClassMap : ClassMap<Home>
{
    public FullHomeClassMap()
    {
        UnMap(x => x.Doors)
        HasMany(x => x.Doors).Cascade.All();
    }
}