Does this library support generating of xml (not xhtml)? what's the top 
level call? I tried

xml_ { ...} and it dies with
irb(main):021:0> doc = xml_ { p_ "a" }
NoMethodError: undefined method `create' for nil:NilClass
        from c:/ruby/lib/ruby/gems/1.8/gems/xx-0.1.0/lib/xx.rb:197:in 
`method_missing'
        from (eval):10:in `xml_'
        from c:/ruby/lib/ruby/gems/1.8/gems/xx-0.1.0/lib/xx.rb:208:in `send'
        from c:/ruby/lib/ruby/gems/1.8/gems/xx-0.1.0/lib/xx.rb:208:in 
`method_missing'
        from (irb):21
        from :0
irb(main):022:0>

Thanks.