class RouteSetV4

Provides mutable access over a set of system's IPv4 routes.

The system maintains a single global routing table. A route set offers an

isolated window into a subset of the global routing table: clients are free

to manage the routes within their own route set, but not the route set of

others. Thus the global routing table represents the union of all existing

route sets. A route must be removed from all route sets to which it belongs

before it will be removed from the global table.

This protocol encodes the lifetime of the route set. Closing the client end

removes the route set, and will also remove any routes that were

solely-owned by this route set.

Note that the system reserves the right to remove routes out from underneath

this route set. This will always manifest as a `removed` event on the

[`fuchsia.net.routes/WatcherV4`] protocol.

If the route table backing this route set is removed, then this protocol

will be closed with a `ZX_ERR_UNAVAILABLE` epitaph.