re: superclass/rails3 yeah I guess so ;> 
it wraps `self.class` into `ConnectionPoolNameDecorator` all the time and finally fails with:

```shell
<"undefined method `connection_pool_name' for ActiveRecordShards::ConnectionPoolNameDecorator:Class">
``` 

Don't have any reasonable solution yet. 

I'm using this [test](https://github.com/lukkry/active_record_shards/commit/866c394fc4ce214171c441cdc45119508cf601f9) (it's probably good only for rails 3 & 4):
```ruby
  it "raises an exception if a connection is not found" do
    ActiveRecord::Base.on_shard(0) do
      ActiveRecord::Base.connection_handler.remove_connection(Ticket)
      assert_raises(ActiveRecord::ConnectionNotEstablished) do
        ActiveRecord::Base.connection_handler.retrieve_connection_pool(Ticket)
        assert_using_database('ars_test_shard0', Ticket)
      end
    end
  end
```