     
     public func representation(using storageType: MediaType, properties: [PropertyKey : Any]) -> Data? {
         
-        let image = base as? AnyImage ?? base.image(option: .fileBacked)
+        let image = base as? AnyImage ?? self.image(option: .fileBacked)
         guard image.width > 0 && image.height > 0 else { return nil }
         
         let Encoder: ImageRepEncoder.Type


public struct ImageRep {
    
    fileprivate let base: ImageRepBase
    
    private init(base: ImageRepBase) {
        self.base = base
    }
}


    }
    
    public func page(_ index: Int) -> ImageRep {
        return cache.lck.synchronized {
            if cache.pages[index] == nil {
                cache.pages[index] = ImageRep(base: base.page(index))
            }
            return cache.pages[index]!
        }
    }
    
    fileprivate func image(option: MappedBufferOption) -> AnyImage {
        return cache.lck.synchronized {
            if cache.images[option] == nil {
                cache.images[option] = base.image(option: option)
            }
            return cache.images[option]!
        }
    }
}

