 undefined callbacks throws");

  test(t => {
    let p = window.trustedTypes.createPolicy('TestPolicyScriptURL10', {
      createHTML: createHTMLJSWithThreeArguments,
      createScript: createScriptJSWithThreeArguments,
      createScriptURL: createScriptURLJSWithThreeArguments
    });
    assert_equals("abc", p.createHTML("a", "b", "c").toString());
    assert_equals("abc", p.createScript("a", "b", "c").toString());
    assert_equals("abc", p.createScriptURL("a", "b", "c").toString());
    assert_equals(