Does new stoptrail order in notify_order() refer to the previous or the coming candle?

[NewestTrader]

Hi,

I am presently looking at the stoptrail functionality.

In my next() method, at time A I generate a buy().
Afterwards I wait in notifyorder() until this buy was 'Completed'.

After it got 'Completed', being still in notifyorder(), I generate a subsequent stoptrail sell order:
self.sell( exectype=bt.Order.StopTrail,trailamount=X)

My question is:
does this sell order initially take the close value of the candle A into account or the close value of the coming candle A+1?

Thanks in advance!