anchor.diff:        `(let  ((,s-name ,stream)) ,content)
         `(with-output-to-string (,s-name) ,content)))
   
  -(defmacro buffer-xml-output ((&optional stream) &body body)
  +(defmacro buffer-xml-output ((&optional stream sink) &body body)
     "buffers out sax:events to a sting
   
      xml parameters like <param:foo param:type=\"string\"><div>bar</div></param:foo>
  
positive.code:               (sax:end-document cxml::*sink*))))
        (%enstream stream out-str content))))
  
  (defmacro %with-snippet ((type &optional stream) &body body)
    "helper to define with-html-snippet and with-xhtml-snippet"
    (assert (member type '(with-html-document with-xhtml-document)))
    (alexandria:with-unique-names (out-str)
  
negative.code:   "
    (alexandria:with-unique-names (out-str)
      (let ((content
              `(let ((cxml::*sink* (or ,sink (make-character-stream-sink ,out-str)))
                     (cxml::*current-element* nil)
                     (cxml::*unparse-namespace-bindings* cxml::*initial-namespace-bindings*)
                     (cxml::*current-namespace-bindings* nil))
  