Revert "Add version validation for LookupMap, also add unittest directly in LookupMap."

pkg/lookup_map/test/lookup_map_test.dart

-// Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-
-import 'package:lookup_map/lookup_map.dart';
-
-import 'package:test/test.dart';
-
-class Key {
-  final int id;
-  const Key(this.id);
-}
-
-class A{}
-const B = const Key(1);
-class C{}
-
-main() {
-  test('entries constructor', () {
-    var m = const LookupMap(const [
-        A, "the-text-for-A",
-        B, "the-text-for-B",
-        1.2, "the-text-for-1.2"]);
-    expect(m[A], 'the-text-for-A');
-    expect(m[B], 'the-text-for-B');
-    expect(m[1.2], 'the-text-for-1.2');
-    expect(m[C], null);
-    expect(m[1.3], null);
-  });
-
-  test('pair constructor', () {
-    var m = const LookupMap.pair(A, "the-text-for-A");
-    expect(m[A], 'the-text-for-A');
-    expect(m[B], null);
-  });
-
-  test('nested lookup', () {
-    var m = const LookupMap(const [],
-        const [const LookupMap.pair(A, "the-text-for-A")]);
-    expect(m[A], 'the-text-for-A');
-    expect(m[B], null);
-  });
-
-  test('entry shadows nested maps', () {
-    var m = const LookupMap(const [
-      A, "the-text-for-A2",
-    ], const [
-      const LookupMap.pair(A, "the-text-for-A1"),
-    ]);
-    expect(m[A], 'the-text-for-A2');
-  });
-
-  test('nested maps shadow in order', () {
-    var m = const LookupMap(const [ ], const [
-      const LookupMap.pair(A, "the-text-for-A1"),
-      const LookupMap.pair(B, "the-text-for-B2"),
-      const LookupMap.pair(A, "the-text-for-A2"),
-      const LookupMap.pair(B, "the-text-for-B1"),
-    ]);
-    expect(m[A], 'the-text-for-A2');
-    expect(m[B], 'the-text-for-B1');
-  });
-
-  // This test would fail if dart2js has a bug, but we keep it here for our
-  // sanity.
-  test('reachable lookups are not tree-shaken', () {
-    var m = const LookupMap(const [
-      A, B,
-      B, C,
-      C, 3.4,
-    ]);
-    expect(m[m[m[A]]], 3.4);
-  });
-}