Implement disc volume class.
Add mock to requirements.
Add file system backend.
Implement disc volume class.
Add file system backend.
Refactor. Move.
Refactor.
Add value extractors.
Add System Verificators.
Refactor.
Add description to value extractor.
Refactor.
Add specialized exceptions for RangeVerificator boundries.
Add Logger.
Add verification suit.
Add date to verification suit.