As I mentionned yesterday, llok at ScalaTest [Eventually](http://doc.scalatest.org/2.0/index.html#org.scalatest.concurrent.Eventually) (adding ` with Eventually with IntegrationPatience` to the test class)
```scala
eventually {
  // The lag should now be cached
  checkCachedAndPersistedLagValues(service, newMember.token, newMember.node, newLag)
}
```
I don't know what checkCachedAndPersistedLagValues does, but I guess it uses ScalaTest assertions.