jboner/akka — comment on commit 603a8ed034f0489cb1330e81d1159640b9432e16
File: akka-actor/src/main/scala/akka/actor/Extension.scala line 29
By rkuhn:

My opinion is that BOTH of them should throw an exception. ExtensionId.apply() should only work after having registered the extension. Alternatively we could go completely the other way and remove loadExtensions() completely, instead relying only on JIT-registration. But that has the “duplicate extension” problem unless we take special care (and I’m not even sure what that means).