Simple example of using persistent_storage in a worker under supervision.
See: https://github.com/cellulose/persistent_storage
Start it with iex -S mix and watch the debug output.
When Storer.Worker is started, it initializes the storage location (/tmp/storer) and then sends itself a message. A second later, when it receives the message, it writes a value. It then sends itself another message. When that message is received, it retrieves the value from storage.