stsRouter.Methods(http.MethodPost).MatcherFunc(func(r *http.Request, rm *mux.RouteMatch) bool {
		ctypeOk := wildcard.MatchSimple("application/x-www-form-urlencoded*", r.Header.Get(xhttp.ContentType))
		authOk := wildcard.MatchSimple(signV4Algorithm+"*", r.Header.Get(xhttp.Authorization))
		noQueries := len(r.URL.RawQuery) == 0
		return ctypeOk && authOk && noQueries
	}).HandlerFunc(httpTraceAll(sts.AssumeRole))

     *
     * @param ctype2
     *            The array of character types to set up.
     */
    protected static void setup(final byte[] ctype2) {
        wordChars(ctype2, 'a', 'z');
        wordChars(ctype2, 'A', 'Z');
        wordChars(ctype2, '0', '9');
        wordChar(ctype2, '@');
        wordChar(ctype2, '|');
        wordChar(ctype2, '_');
        wordChar(ctype2, '?');
        wordChar(ctype2, '>');