function isAt isAt(item: OwnedItem | null | undefined,username: string | undefined,slug: string | undefined): boolean Checks whether item, a dump or a playlist, is the one a page's /@username/…/slug names, the name in any case. A page that already shows it needn't fetch it again when its URL changes to its current path. Parameters item: OwnedItem | null | undefined username: string | undefined slug: string | undefined Return Type boolean