code: func (rk *rowKey) encode() (v string) {
  	// Write the final key to "key": (base64(HASH)~hex(INDEX))
  	withRowKeyBuffers(func(rkb *rowKeyBuffers) {
  		rkb.appendPathPrefix(rk.pathHash)
  		rkb.appendBytes([]byte("~"))
  		rkb.appendInt64(rk.index)
  		rkb.appendBytes([]byte("~"))
  		rkb.appendInt64(rk.count)
  		v = rkb.value()
  	})
  	return
  }
docs: // newRowKey instantiates a new rowKey from its components.