code: func (c *Cluster) RemovePeer(regionID, storeID uint64) {
  	c.Lock()
  	defer c.Unlock()
  
  	c.regions[regionID].removePeer(storeID)
  }
docs: // RemovePeer removes the Peer from the Region. Note that if the Peer is leader,
  // the Region will have no leader before calling ChangeLeader().