code: func NewVacuum(ctx context.Context, driver driver.StorageDriver) Vacuum {
  	return Vacuum{
  		ctx:    ctx,
  		driver: driver,
  	}
  }
docs: // vacuum contains functions for cleaning up repositories and blobs
  // These functions will only reliably work on strongly consistent
  // storage systems.
  // https://en.wikipedia.org/wiki/Consistency_model
  // NewVacuum creates a new Vacuum