     public var base64Representation: String
     {
         var output = ""
-        for sixbitInt in (self.bytesToSixbitArray.map { Int($0) }) {
+        for sixbitInt in (self.bytesToSextetArray.map { Int($0) }) {
             output += base64Chars[sixbitInt]
         }
         while output.characters.count % 4 != 0 { output += "=" }

    /// returns an array of bytes
    /// - precondition: `self` is base-64 text
    public var base64ToBytes: [UInt8] {
        return characters.map { String($0) }.filter { $0 != "=" }.map { UInt8(base64Chars.indexOf($0)!) }.sixbitArrayToBytes
    }
    
    public var asciiToBase64: String {

        let sixes: [UInt8] = [19, 22, 5, 46]
        let eights: [UInt8] = [77, 97, 110]
        
        assert(sixes.sextetArrayToBytes == eights)
        assert(eights.bytesToSextetArray == sixes)

        let t1 = "Man"
        let e1 = "TWFu"
