static Pair<LS, O> prepareEvalWithDollarVars_assertAllVarsSet(S code, SS values) {
  Set<S> vars = tok_dollarVarTokens(javaTok(code));
  for (S v : vars)
    if (!containsKey(values, v))
      fail("No value for " + v);
  ret prepareEvalWithDollarVars(code, vars);
}