anchor.diff:  
   ```yml
   steps:
  -  - label: "\:hammer\:"
  +  - label: "🔨"
       command: "scripts/test"
     
     - wait
     
  -  - label: "\:rocket\:"
  +  - label: "🚀"
       command: "scripts/deploy"
       branches: "master"
       concurrency_group: "my-app-deploy"
  
positive.code: ```yaml
  steps:
    - block: "Release to production?"
    - label: "\:ecs\: \:rocket\:"
      concurrency_group: "rails-app-deploy"
      concurrency: 1
      plugins:
  
negative.code: 
  ```yml
  steps:
    - label: "🚀"
      command: "scripts/deploy"
      branches: "master"
      concurrency_group: "my-app-deploy"
      concurrency_limit: 1
  ```
  
  The "🚀" step in the deployment example above uses the concurrency attributes `concurrency_group` and `concurrency_limit`. These work together to ensure that no matter how many builds are triggered on this pipeline at once, no "🚀" steps can run in parallel. It also prevents deploys clashing and attempting to write to the same resources. 
  
  [screenshot of a deploy pipeline]
  
  