title: How long does IBM's Watson Dialog Service retain conversation and client details?
body: <p>I'm just getting started with Watson Dialog service and I'm trying to ensure that I don't allow my users to attempt to resume a conversation with the bot if their conversation session is no longer valid. Is there an expiration on Dialog conversations at all? Or does IBM simply store conversations forever?</p>
  
  <p><strong>EDIT:</strong></p>
  
  <p>If there is a method to determine whether a Dialog Conversation has expired, please provide a link to documentation, or an example, of said method.</p>