'Save the validating log.
Parameters
args : dictionary, items to save.
Examples
>>> db.valid_log(time=time.time(), {\'loss\': loss, \'acc\': acc})'

@AutoFill
def valid_log(self, args={}):

    _result = self.db.ValidLog.insert_one(args)
    _log = self._print_dict(args)
    print ('[TensorDB]    ValidLog:    ' + _log)
    return _result
