Resolves the watch request into a Watcher, and fires off to etcd.
inRange instructs the builder to watch keys in the specified byte range.
Sets a single key to be watched.
Requests only changes for the given kinds of operations.
Prefix instructs the watcher to watch all keys with the given prefix.
Watch starting from a specific revision.
Instructs the watcher to return the previous key/value pair in updates.
WatchBuilder is used for creating etcd watchers. The created watchers are resilient against disconnections, automatically resubscribing and replaying changes when reconnecting.