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`Client` only supports connecting by IP.  The simplest client you can build.
You want your users to have an easy life though, so you want to also support connecting by domain name.
You could add a new `connect` overload to `Client`, but now client isn't as simple as possible, it does two things (connection and DNS resolution).
You could derive from `Client` and have a `DNSClient`, but that isn't as nice of an interface for users.
You could add an extension method and have the nice interface but also allow users to connect via DNS.