[Zope] Why can't I subclass a ZSQLMethod?

I want to wrap a presentation layer around ZSQLQueries, so that they will have methods to generate an input form [1] for the query, and generate tabular results if so desired. I tried to create a ZClass to do this, but I can't subclass from a ZSQLMethod. Any other ideas on how to do this (besides a class where you have to tell it the ZSQLMethod to use)? -- cary [1] Using sql.arguments_str to find out the arguments. Finding THAT was a struggle!