anchor.diff:  
   At the start of your `pipeline.yml`, add a step to build an image with the Docker plugin. In this example, we use the `docker-compose` plugin to prebuild the `app` image and upload it to a registry:
   
  -```
  +```yml
   steps:
     - name: "Docker Build"
       plugins:
  
positive.code: 
  Another example of a production `docker-compose.yml` configuration is from the [buildkite-agent Golang source code](https://github.com/buildkite/agent):
  
  ```
  version: '2.1'
  services:
    agent:
  
negative.code: 
  To run later steps in the image you have built, use the `plugins` attribute on command steps. This example runs a test suite concurrently in the `app` image that was built in the previous example:
  
  ```yml
  - name: "Docker Test %n"
    command: test.sh
    parallelism: 25
    plugins:
      docker-compose#v2.0.0:
        run: app
  ```
  
  For more examples and information on using this plugin, have a look at the [Docker Compose Plugin on GitHub](https://github.com/buildkite-plugins/docker-compose-buildkite-plugin).
  