static S quickRunDex(byte[] dex) {
  S s = loadDex(dex, false);
  new Matches m;
  if (!match("OK, injection id: *", s, m)) fail(s);
  S injectionID = m.unq(0);
  O paa = call(getJavaX(), "findInjection", injectionID);
  O c = get(paa, "mainClass");
  call(getJavaX(), "setVars", c, null);
  try {
    ret ok(callOpt(c, "_calc"));
  } finally {
    call(getJavaX(), "removeInjection", paa);
  }
}