docs: def revoke_session():
      """Revoke a session."""
      form = RevokeForm(request.form)
      if not form.validate_on_submit():
          abort(403)
  
      sid_s = form.data['sid_s']
      if SessionActivity.query.filter_by(
              user_id=current_user.get_id(), sid_s=sid_s).count() == 1:
          delete_session(sid_s=sid_s)
          db.session.commit()
          if not SessionActivity.is_current(sid_s=sid_s):
              # if it's the same session doesn't show the message, otherwise
              # the session will be still open without the database record
              flash('Session {0} successfully removed.'.format(sid_s), 'success')
      else:
          flash('Unable to remove the session {0}.'.format(sid_s), 'error')
      return redirect(url_for('invenio_accounts.security'))