def open(self):
        if not self.filename:
            raise ValueError("Can only open on-disk databases")
        self.db = dbm.open(self.filename, "w") #raises anydbm.error
        try:
            if self.db["--Reserved--type"] != self.type:
                raise ValueError("Not a %s database" % self.type)
        except KeyError:
            raise ValueError("Not a recognized database")
Recursively finds pipeline through layers of groupExecs
dataset/ETHPy150Open kuri65536/python-for-android/python3-alpha/python-libs/gdata/tlslite/BaseDB.py/BaseDB.open--crossover with--dataset/ETHPy150Open VisTrails/VisTrails/vistrails/gui/collection/vis_log.py/QLogView.get_execution_pipeline