This member is added by an implicit conversion from ReachabilityEvent to
any2stringadd[ReachabilityEvent] performed by method any2stringadd in scala.Predef.
This member is added by an implicit conversion from ReachabilityEvent to
StringFormat[ReachabilityEvent] performed by method StringFormat in scala.Predef.
Marker interface to facilitate subscription of both UnreachableMember and ReachableMember.