async cleanUp() {
        if (this.fileToDelete === null) {
            return;
        }

        try {
            await fs.remove(this.fileToDelete);
        } catch (err) {
            logging.error(new errors.InternalServerError({
                err: err,
                context: tpl(messages.couldNotCleanUpFile.error),
                help: tpl(messages.couldNotCleanUpFile.context)
            }));
        }

        this.fileToDelete = null;
    }
Step 5:
Remove files after we're done (abstracted into a function for easier testing)
@returns {Promise<void>}