code: @Override
    protected Routing<P> computeRouting() {
      Routee<P> least = null;
      int leastCount = Integer.MAX_VALUE;
      for (Routee<P> routee : routees()) {
        int count = routee.pendingMessages();
        if (count == 0) {
          least = routee;
          break;
        }
        else if (count < leastCount) {
          least = routee;
          leastCount = count;
        }
      }
      return Routing.with(least);
    }
docs: /* @see io.vlingo.actors.Router#computeRouting()