def onTransactionAmountChanged(self, message):
        transaction = message.data
        if transaction.Parent == self:
            debug.debug("Updating balance because I am %s: %s" % (self.Name, transaction))
            self.Balance = sum((t.Amount for t in self.Transactions))
        else:
            debug.debug("Ignoring transaction because I am %s: %s" % (self.Name, transaction))