Initialize mirador with manaifestJson instead of manifensURI

[tkitov]

In order to save time loading mirador, I want to save the manifestJson in cache and then in the next manifest loading check if this manifest exists in cache, and if so - use that json (and avoid calling API again). The problem is I can't find how to load the json instead of the manifestUri. I tried initializing like this: Mirador.viewer({ windows: [{ manifestJson: jsonFromCache.... but it doesn't work. Is there a way of loading json instead of manifentId?