(println "servlet-request class is" (str (class (:servlet-request request))))
  (println "servlet-request ancestors are" (str (ancestors (class (:servlet-request request)))))
  (println "servlet-request isa? javax.servlet.http.HttpServletRequest" (isa? (:servlet-request request) javax.servlet.http.HttpServletRequest))

class is:
com.google.appengine.api.blobstore.dev.UploadBlobServlet$2

ancestors are:
java.lang.Object
javax.servlet.ServletRequest
javax.servlet.http.HttpServletRequestWrapper
javax.servlet.ServletRequestWrapper
javax.servlet.http.HttpServletRequest

isa? is false