You can download the example using Git along with the source code of any project organized at gerrit.wikimedia.org using the following Git Bash command.
$ git clone ssh://<user_name>@gerrit.wikimedia.org:29418/mediawiki/extensions/examples
The git clone command clones a directory into a new directory; in other words gets a copy of an existing repository. When you run the above command, you will get a screenshot similar to the following.
The above command clones the 'examples' repository and receives the objects, files, etc. from that repository and stores it in your local branch.