From a quick test:

```
>> require 'etcd'
=> true
>> o = Object.new
=> #<Object:0x007f8b629b6e38>
>> c = Etcd.client
=> #<Etcd::Client:0x007f8b62858640 @host="127.0.0.1", @port=4001, @read_timeout=60, @allow_redirect=true>
>> o.instance_eval { c.watch('/') }
=> #<OpenStruct action="SET", key="/test/bar", prevValue="Hello world", value="Hello woas", index=23>
```