A file archive is a single file which can contain the contents, names and other metadata of multiple files. These can make backup and transport of files more convenient, and can often make compression more efficient. We often refer to tools that can create or manipulate these as file archivers. There are a vast number of archive formats: on $*$nix$-$like systems, tar is common; whereas on Windows, Zip is common. Wikipedia's list of archive formats is a marvellous rabbit$-$hole to explore. In this assignment, you will be implementing rain, a file archiver for the drop format. The drop format is made up of one or more droplets; where a droplet records one file system object; This format is described in more detail below.