def get_next_id(self):
        try:
            query = {'_id': 'last_id'}
            update = {'$inc': {'id': 1}}
            fn = self.db.internal.find_and_modify
            row = fn(query, update, upsert=True, new=True)
        except Exception as e:
            raise DatabaseException(e)
        return row['id']
def testDeviceWrapper(self):
    wrapper_type = rnn_cell_wrapper_v2.DeviceWrapper
    x = array_ops.zeros([1, 3])
    m = array_ops.zeros([1, 3])
    cell = rnn_cell_impl.GRUCell(3)
    wrapped_cell = wrapper_type(cell, "/cpu:0")
    children = wrapped_cell._trackable_children()
    wrapped_cell.get_config()  # Should not throw an error
    self.assertIn("cell", children)
    self.assertIs(children["cell"], cell)

    outputs, _ = wrapped_cell(x, m)
    self.assertIn("cpu:0", outputs.device.lower())