 
 protocol Diffable {
     var diffIdentifier: AnyHashable { get }
-}
-
-enum DiffOption<T> {
-    case equality
-    case custom((T, T) -> Bool)
 }
 
 /// https://github.com/Instagram/IGListKit/blob/master/Source/IGListDiff.mm

        }
    }
    
    static func diffing<T: Diffable & Equatable>(oldArray:Array<T>, newArray:Array<T>, option: DiffOption<T> = .equality) -> Result {
        // symbol table uses the old/new array `diffIdentifier` as the key and `Entry` as the value
        var table = Dictionary<AnyHashable, Entry>()
        

            if (oldIndex < oldArray.count) {
                let n = newArray[i]
                let o = oldArray[oldIndex]
                if n != o {
                    entry.updated = true
                }
            }
            
