go =>
  Map = new_map([1=one,2=two,3=three,4=four]),
  foreach(K=V in Map)
    println(K=V)
  end,
  nl,

  println(keys=Map.keys),
  foreach(K in Map.keys.sort)
    println(K=Map.get(K))
  end,
  nl,

  println(values=Map.values),
  foreach(V in Map.values.sort)
    % This works but gets a warning: nonlocal_var_in_iterator_pattern
    % println(V=[K : K=V in Map])

    % No warning:
    println(V=[K : K=V1 in Map,V1 == V])
  end,
  nl.