Single Responsibility Principle: Responsibility unknown [closed]

Question

I store sessions in a SessionManager. The session manager has a dependency to ISessionPersister.

SessionManager

private readonly ISessionPersister sessionPersister;
public SessionManager(ISessionPersister sessionPersister)
{
    this.sessionPersister = sessionPersister;
}

ISessionPersister

public interface ISessionPersister : IDisposable
{
    void PersistSessions(Dictionary<string, ISession> sessions);
}

Q: If my application shuts down how / where do I call PersistSessions? Who is responsible?

First Approach: Use Dispose in SessionManager

protected virtual void Dispose(bool disposing)
{
    if (disposing)
    {
       if (this.sessionPersister != null && this.sessionMap != null && this.sessionMap.Count > 0)
       {
           this.sessionPersister.PersistSessions(this.sessionMap);
        }
    }
}

Is that the way to go or are there any better solutions?