svoid test_paramsPlus() {
  assertEqualsVerbose(ll(a := "b"), asList(paramsPlus(litobjectarray(a := "b"), null)));
  assertEqualsVerbose(ll(a := "b"), asList(paramsPlus(null, a := "b")));
  assertEqualsVerbose(ll(a := "b", c := "d"), asList(paramsPlus(litobjectarray(a := "b"), c := "d")));
  assertEqualsVerbose(ll(a := "e"), asList(paramsPlus(litobjectarray(a := "b"), a := "e")));
}