The unit test `remainder()` checks the process' memory map for leftover data in the working buffer when testing with this feature enabled. It is still unlikely data will remain even without this feature, depending on your system; you should only use it if you are very paranoid.
To see a more detailed explenation run `chacha20 help`.
## Formats
The key and IV is expected/generated in base64 format.
The key and IV sizes respectively are 32 and 12 bytes.
The ciphertext input and output is raw binary data. You can encode this to text formats if you want with whatever tool you choose (Example with `base64` below.)