Add tests for the `Vary: Cookie` header
Add tests for the `Vary: Cookie` header

dawran6/flask,pallets/flask,drewja/flask,drewja/flask,dawran6/flask,mitsuhiko/flask,tristanfisher/flask,tristanfisher/flask,pallets/flask,fkazimierczak/flask,fkazimierczak/flask,pallets/flask,drewja/flask,mitsuhiko/flask,fkazimierczak/flask