Full Schema Sample

I am looking for any schema that has a set of all the possible tags and 
attrributes with all combination. I need to use this for testing 
purposes or an xsl transformation. I know there's a sample for "purchase 
order" but that is not even close to perfect. It's missing a lot of tags 
(ie, choise, all, ....) and another possible combination. Does anyone 
know where I can find this perfect Schema.