@spec dir(format()) :: String.t()

Returns the storage directory for a given type.

There is no check if the format passed is included in the format/0 type.

@spec file(format(), String.t()) :: String.t()

Returns the full path to a file.

No check is performed if the file exists.

@spec files(format()) :: [String.t()]

Returns a list of included files (full path) for a given type.

If you pass an unknown format not specified by the format/0 type an empty list will be returned.