title: Python Telethon get_messages offset
body: <p>I'm using <code>Telethon</code> in my <code>Python</code> project. I'm using this code to get messages from a Group in Telegram:</p>
  
  <pre><code>full_msg_list = self.client.get_messages(GROUPID, limit=200)
  </code></pre>
  
  <p>Is there any way to get the next 200 messages from the group?</p>