On this branch, the exercise is to incrementally add changes, running the tests after each one. The end state should be the same as the branch 'with_broken_tests', you just get there in small steps.
To apply each incremental change, use these commands:
git apply pick1.patch
git apply pick2.patch
git apply pick3.patch
git apply pick4.patch
git apply pick5.patch
git apply pick6.patch
Note: to un-apply a patch use:
git apply -R pickX.patch