Fluent NHibernate Object Referencing Instance of Itself / Self Referencing, Error “Repeated column in mapping for collection”

I came across a problem with a Schema Fluent Nhibernate was generating for me yesterday.  I was getting the error message “Repeated column in mapping for collection”. I had an object, let’s call it “Item” which referenced instances of the same type, let’s call them “AssociatedItems”. Thinking of a simple real-life example, when you do…