// Manages the complete lifecycle of a buy.
// When a bool can be read from interrupt, the buy is aborted.
func (a *BuyActivity) PerformBuy(log bitwrk.Logger, interrupt <-chan bool, workFile cafs.File) (cafs.File, error) {
a.workFile = workFile.Duplicate()
file, err := a.doPerformBuy(log, interrupt)
if err != nil {
a.lastError = err
}
a.alive = false
return file, err
}
