/// <summary>
/// Fetches the thumbnail for the given asset.
/// </summary>
/// <param name="asset">The asset for which to fetch the thumbnail.</param>
/// <param name="options">The extra options, if any (can be null).</param>
/// <param name="callback">The callback to call when the fetch finishes (optional).</param>
public static void FetchThumbnail(PolyAsset asset, PolyFetchThumbnailOptions options,
FetchThumbnailCallback callback = null)
{
CheckInitialized();
PolyMainInternal.Instance.FetchThumbnail(asset, options, callback);
}