Has anyone implemented this, or know if it would be difficult to implement this/have any pointers?

public static SpatialRelationCriterion IsWithinDistance(string propertyName, object anotherGeometry, double distance)
{
    // TODO: Implement
    throw new NotImplementedException();
}

from NHibernate.Spatial.Criterion.SpatialRestrictions

I can use "where NHSP.Distance(PROPERTY, :point)" in hql. But want to combine this query with my existing Criteria query.

for the moment I'm creating a rough polygon, and using

criteria.Add(SpatialRestrictions.Intersects("PROPERTY", myPolygon));