You need it otherwise you get:

```
org.elasticsearch.common.inject.CreationException: Guice creation errors:

1) Binding points to itself.
  at org.elasticsearch.action.bench.BenchmarkModule.configure(BenchmarkModule.java:40)
```

Although it is currently a no-op, I'd like to keep it b/c it is a useful hook for plugging in a mock service class from tests.