How can I create a `FakeApplication` to run my tests using my `dev.conf` instead of the default `application.conf`?

My current test consists of the following construct:

```
Map<String, String> map = new HashMap<>();
map.put("config.file", "/path/to/dev.conf");
FakeApplication fakeApplication = fakeApplication(map);
TestServer testServer = testServer(3333, fakeApplication);
// testServer.start();
running(testServer, HTMLUNIT, new F.Callback<TestBrowser>() {
    public void invoke(TestBrowser browser) {
        //do something
    }
});

```

This code adapted from [the Play Framework Documentation about writing test](http://www.playframework.org/documentation/2.0.4/JavaFunctionalTest) throws the following Exception, as the default `application.conf` does not work on my development-system. If I uncomment `testServer.start();` I can see it even more clearly.

```
[WARN] [01/01/2013 18:36:59.505] [pool-4-thread-3] [Dispatchers] Dispatcher [akka.actor.promises-dispatcher] not configured, using default-dispatcher
[WARN] [01/01/2013 18:36:59.521] [play-akka.actor.default-dispatcher-2] [Dispatchers] Dispatcher [akka.actor.actions-dispatcher] not configured, using default-dispatcher
[error] Test test.ApplicationTest.runInBrowser failed: Server is not started!
[error]     at scala.sys.package$.error(package.scala:27)
[error]     at play.api.test.TestServer.stop(Selenium.scala:117)
[error]     at play.test.Helpers.stop(Helpers.java:325)
[error]     at play.test.Helpers.running(Helpers.java:355)
[error]     at test.ApplicationTest.runInBrowser(ApplicationTest.java:74)
[error]     ...

```

I assume the line

```
map.put("config.file", "/path/to/dev.conf");

```

is wrong and has to be adapted. But how?