ion data via the session fingerprint and callback(err, data)
#set(hash, data, callback)   Commit the session for the fingerprint and callback(err)
</code></pre>

<p>Your store may also want to comply with the default MemoryStore, by providing:</p>

<pre><code>#clear(callback)            Clear all sessions and callback(err)
#all(callback)              Fetches all active sessions and callback(err, sessions)
#length(callback)           Fetches the total number of sessions and callback(err, len)
</code></pre>

