code: func (ctx *protoKeyValIterator) GetNext() (kv keyval.ProtoKeyVal, stop bool) {
  	pair, stop := ctx.delegate.GetNext()
  	if stop {
  		return nil, stop
  	}
  
  	return &protoKeyVal{pair, ctx.serializer}, stop
  }
docs: // GetNext returns the following item from the result set.
  // When there are no more items to get, <stop> is returned as *true*
  // and <kv> is simply *nil*.