Question 028
### How can you ensure that a workflow called `Deploy Prod` is always running at most one at a time?
> https://docs.github.com/en/actions/using-workflows/workflow-syntax-for-github-actions#concurrency
1. [x] Use `concurrency` on workflow level
```yaml
concurrency: ${{ github.workflow }}
```
1. [ ] Use `queue` on workflow level
```yaml
queue: ${{ github.workflow }}
```
1. [ ] Use `order` on workflow level
```yaml
order: ${{ github.workflow }}
```
1. [ ] Use `parallel` on workflow level
```yaml
parallel: ${{ github.workflow }}
```