anchor.diff:  . Allows tar file auto-extraction in the image, for example, `ADD app.tar.gz /opt/var/myapp`.
   . Allows files to be downloaded from a remote URL. However, the downloaded files will become part of the image. This causes the image size to bloat. So its recommended to use `curl` or `wget` to download the archive explicitly, extract, and remove the archive.
   
  -=== Import and export images
  +==== Import and export images
   
   Docker images can be saved using `save` command to a .tar file:
   
  
positive.code: 
  === Create your first Docker image
  
  _Hello World_ Dockerfile is shown:
  
  .Hello World Dockerfile
  [source, text]
  
negative.code: 
    docker run -it mywildfly
  
  === Deploy Java EE 7 Application
  
  Create a new text file _Dockerfile_ in an empty directory:
  
  