open fun isArtworkValid(artwork: Artwork): Boolean
Called every time an image is loaded (even if there is a cached
image available). This gives you an opportunity to circumvent the
typical loading process and remove previously cached artwork on
demand. The default implementation always returns true.
In most cases, you should proactively delete Artwork that you know is not valid rather than wait for this callback since at this point the user is specifically waiting for the image to appear.
The MuzeiArtProvider will call onInvalidArtwork for you
if you return false - there is no need to call this
manually from within this method.
artwork - The Artwork to confirm
Return
Whether the Artwork is valid and should be loaded