How can I download only a specific folder or directory from a remote Git repository hosted on GitHub?

Say the example GitHub repository lives here:

git@github.com:foobar/Test.git

Its directory structure:

Test/
├── foo/
│   ├── a.py
│   └── b.py
└── bar/
    ├── c.py
    └── d.py

I want to download only the foo folder and not clone the whole Test project.