def _tx():
dest_transfer = Account_transfer.get_by_key_name(str(source_transfer.key()), parent=source_transfer.counter_account.key())
if not dest_transfer:
dest_transfer = Account_transfer(
parent = source_transfer.counter_account.key(),
key_name = str(source_transfer.key()),
self_account = source_transfer.counter_account,
counter_account = source_transfer.key().parent(), #same as source_transfer.counter_account
counter_transfer = source_transfer,
currency_type = source_transfer.currency_type,
amount = -source_transfer.amount,
is_committed = True)
account = Account.get(dest_transfer.self_account.key())
account.balance += source_transfer.amount # add negative amount
db.put([account, dest_transfer])
return dest_transfer
