Sends the message to a first, random picked, routee,
then wait a specified interval and then send to a second, random picked, and so on till one full cycle.
schedules sending messages to routees
expecting at least one reply within this duration, otherwise
it will reply with akka.pattern.AskTimeoutException in a akka.actor.Status.Failure
duration after which next routee will be picked
execution context used by scheduler
Pick the destination for a given message.
Pick the destination for a given message. Normally it picks one of the
passed routees, but in the end it is up to the implementation to
return whatever Routee to use for sending a specific message.
When implemented from Java it can be good to know that
routees.apply(index) can be used to get an element
from the IndexedSeq.