def savepoint_rollback(sid, using=None):
    if using is None:
        using = DEFAULT_DB_ALIAS
    connection = connections[using]
    connection.savepoint_rollback(sid)
This function is used as a callback replacment to IPython pager function
dataset/ETHPy150Open AppScale/appscale/AppServer/lib/django-1.5/django/db/transaction.py/savepoint_rollback--crossover with--dataset/ETHPy150Open ipython/ipython-py3k/IPython/deathrow/gui/wx/ipshell_nonblocking.py/NonBlockingIPShell._pager