BoltNetwork SetSessionData API example

Hello, in the documentation (BoltNetwork.SetHostInfo) we can find the following:

void SetSessionData(string serverName, string description, int maxPlayers) {

     SessionData sessionData = new SessionData(description, BoltNetwork.maxConnections);
     BoltNetwork.SetHostInfo(serverName, sessionData);

}

https://doc-api.photonengine.com/en/bolt/current/class_bolt_network.html

But, I can't find where is the namespace for use sessionData type :S