Could someone just explain these directions to me in better english?
For the given id in collection: If prop does not contain the key "tracks", then update or set the value for that incomplete prop. If prop does not contain the key "tracks" before you update it, create an empty array before pushing a track to it. If prop does contain the key "tracks" and its value is non-blank, then push the value onto the end of its existing tracks array. If value is blank, delete that prop.