hashmap.put(null, "baz");

    assertEquals(hashmap.toString(), Maps.toStringImpl(hashmap));
  }

  public void testToStringImplWithNullValues() throws Exception {
    Map<String, @Nullable String> hashmap = new HashMap<>();
    hashmap.put("foo", "bar");
    hashmap.put("baz", null);

    assertEquals(hashmap.toString(), Maps.toStringImpl(hashmap));
  }

  @J2ktIncompatible

    hashmap.put(null, "baz");

    assertEquals(hashmap.toString(), Maps.toStringImpl(hashmap));
  }

  public void testToStringImplWithNullValues() throws Exception {
    Map<String, @Nullable String> hashmap = new HashMap<>();
    hashmap.put("foo", "bar");
    hashmap.put("baz", null);

    assertEquals(hashmap.toString(), Maps.toStringImpl(hashmap));
  }

  @J2ktIncompatible

      Map<?, ?> o = (Map<?, ?>) object;
      return map.entrySet().equals(o.entrySet());
    }
    return false;
  }

  /** An implementation of {@link Map#toString}. */
  static String toStringImpl(Map<?, ?> map) {
    StringBuilder sb = Collections2.newStringBuilderForCollection(map.size()).append('{');
    boolean first = true;
    for (Entry<?, ?> entry : map.entrySet()) {
      if (!first) {