mkdir test-repo
cd test-repo/
mkdir submodules
mkdir submodules/a 
mkdir submodules/b
cd submodules/a/
touch a.txt; echo sample text for a.txt >> ./a.txt; git-init; git-add a.txt; git-commit -a -m "First commit on a"
cd ../b/
touch b.txt; echo sample text for b.txt >> ./b.txt; git-init; git-add b.txt; git-commit -a -m "First commit on b"
cd ../a/
git-submodule add ../b/; git-commit -a -m "committing with submodule b"
cd ../../
mkdir super-project
cd super-project/
touch main.txt; echo sample text for main.txt >> ./main.txt; git-init; git-add main.txt; git-submodule add ../submodules/a; git-commit -a -m "First commit on super project";