How do I add Check Constraints in an AttributePropertyConvention in Fluent NHibernate?

Question

First time journey with (Fluent) NHibernate. What I am trying to do is to add conventions for the attributes in System.ComponentModel.DataAnnotations.

How would I add a Check Constraint for the attribute.MinimumLength? Here is my code so far:

Thanks!

using System.ComponentModel.DataAnnotations;
using FluentNHibernate.Conventions;
using FluentNHibernate.Conventions.Instances;

public class StringLengthConvention : AttributePropertyConvention<StringLengthAttribute>
{
    protected override void Apply( StringLengthAttribute attribute, IPropertyInstance instance )
    {        
        // instance.Check is a read-only property?
        // Huh?

        instance.Length( attribute.MaximumLength );
    }
}

:: EDIT ::

This seems to be a feature that has not been ported yet, see: http://code.google.com/p/fluent-nhibernate/issues/detail?id=358