         return false
     }
     
-    //
-    //  Private helpers
+    
+    //
+    //  MARK: Private helpers
     //
     private func obtainKey(key: KeyType) -> SecKeyRef? {
         let tag: String = {

    }
    
    //
    //  Private class functions
    //
    
    private class func obtainKey(tag: String, keySize: Int) -> SecKeyRef? {

import CommonCrypto

public class Heimdall {
    private let publicTag: String
    private let privateTag: String?
    private let keySize: Int
    
    }
    
    public init?(tag: String, keySize: Int = 2048) {
