hasLeaderListener = function hasLeaderListener(msg) {
    if (msg.context === 'leader') {
      if (msg.action === 'death') {
        _this._hasLeader = false;
      }
      if (msg.action === 'tell') {
        _this._hasLeader = true;
      }
    }
  }
Even when the own instance is not applying,
we still listen to messages to ensure the hasLeader flag
is set correctly.