How do I download flutter packages to use it if I was offline?

I wonder if there is a way to download flutter packages for offline using please , so that I can use it always in my flutter projects when I was offline , I don't want to always add the package in pubspec.yaml and pubget , always needs a wifi connection , I want it to download it for once and use it always like a bootstrap , or jquery download files compiled codes ,, I think it can be a little boring for all of the developers that use a package for hundred times and download it awlays and always

you should be able to add a dependency like this

dependencies:
  flutter_dependency:
    git:
      url: local-git-repo-previously-cheched-out