def empty(self, value):
    return value is None
Retrieve timestamp of last modification, in micro-seconds.
dataset/ETHPy150Open AppScale/appscale/AppServer/google/appengine/ext/db/__init__.py/FloatProperty.empty--crossover with--dataset/ETHPy150Open edgewall/trac/tracopt/versioncontrol/svn/svn_fs.py/SubversionNode.get_last_modified