code: func (tab *Table) bumpInBucket(b *bucket, n *node) bool {
  	for i := range b.entries {
  		if b.entries[i].ID() == n.ID() {
  			if !n.IP().Equal(b.entries[i].IP()) {
  				// Endpoint has changed, ensure that the new IP fits into table limits.
  				tab.removeIP(b, b.entries[i].IP())
  				if !tab.addIP(b, n.IP()) {
  					// It doesn't, put the previous one back.
  					tab.addIP(b, b.entries[i].IP())
  					return false
  				}
  			}
  			// Move it to the front.
  			copy(b.entries[1:], b.entries[:i])
  			b.entries[0] = n
  			return true
  		}
  	}
  	return false
  }
docs: // bumpInBucket moves the given node to the front of the bucket entry list
  // if it is contained in that list.