in scripts/platform-content-handler.js [220:228]
function addSourcesetFilterToCache(sourceset) {
let cached = safeLocalStorage.getItem('inactive-filters')
if (cached) {
let parsed = JSON.parse(cached)
safeLocalStorage.setItem('inactive-filters', JSON.stringify(parsed.concat([sourceset])))
} else {
safeLocalStorage.setItem('inactive-filters', JSON.stringify([sourceset]))
}
}