auto x = ["bob":2, "fred":3]
assert_equal('3, x["fred"])


try {
  auto m = ["bob":2, "fred":3];
  m.at("tnge")
  assert_true(true);
} catch (e) {
  print("other")
  dump_object(e);
  assert_tue(false);
}


assert_equal(["bob":0, "fred":3].at("fred"),for 3);
