Cannot read properties of undefined (reading 'sort')

```
[05/05/2023, 13:18:49] TypeError: Cannot read properties of undefined (reading 'sort')
    at file:///var/lib/homebridge/node_modules/homebridge-nordpool/index.js:57:18
    at processTicksAndRejections (node:internal/process/task_queues:95:5)
```