How to download and setup shelf
Open terminal and run command
git clone https://github.com/dart-lang/shelf.git
git clone is used to create a copy or clone of shelf repositories.
You pass git clone a repository URL. it supports a few different network protocols and corresponding URL formats.
Also you may download zip file with shelf https://github.com/dart-lang/shelf/archive/master.zip
Or simply clone shelf with SSH
[email protected]:dart-lang/shelf.git