 
 import Foundation
 
-extension MutableCollection where Indices.Iterator.Element == Index {
+public extension MutableCollection where Indices.Iterator.Element == Index {
     /// Shuffles the contents of this collection.
     mutating func shuffle() {
         let c = count

    }
}

extension Array {
    var randomIndex: Int {
        return Int(arc4random_uniform(UInt32(count)))
    }

    }
}

public extension Array where Element: Equatable, Element: Comparable {
    func repeatablePermutation(_ length: Int? = nil, processor: (([Element]) -> Void)? = nil) -> [[Element]] {
        var allPermutations: [[Element]] = []
        func _repeatablePermutation(_ lengthToGo: Int, remainder: inout [Element], aPermutation: inout [Element]) {
