app/code/Magento/Cron/Console/Command/CronInstallCommand.php

app/code/Magento/Cron/Console/Command/CronRemoveCommand.php

...Cron/Test/Unit/Console/Command/CronInstallCommandTest.php

.../Cron/Test/Unit/Console/Command/CronRemoveCommandTest.php

app/code/Magento/Cron/etc/di.xml

lib/internal/Magento/Framework/Crontab/CrontabManager.php

...nal/Magento/Framework/Crontab/CrontabManagerInterface.php

lib/internal/Magento/Framework/Crontab/README.md

lib/internal/Magento/Framework/Crontab/TasksProvider.php

...rnal/Magento/Framework/Crontab/TasksProviderInterface.php

...agento/Framework/Crontab/Test/Unit/CrontabManagerTest.php

...Magento/Framework/Crontab/Test/Unit/TasksProviderTest.php