Checks the logged-in status of the current session. 
    Expensive (requests a page), so use sparingly! Best practice is to try a request and catch an UnauthorizedError.

    :rtype: bool
    :return: Whether or not the current session is logged-in.

def logged_in(self):
    """Checks the logged-in status of the current session. 
    Expensive (requests a page), so use sparingly! Best practice is to try a request and catch an UnauthorizedError.

    :rtype: bool
    :return: Whether or not the current session is logged-in.

    """
    if self.session is None:
      return False

    panel_url = u'http://myanimelist.net/panel.php'
    panel = self.session.get(panel_url)

    if 'Logout' in panel.content:
      return True

    return False