         return log2f(sizeOfCharacterSet) * Float(string.characters.count)
     }
 
-    private class func NJOPasswordStrength(for entropy: Float) -> NJOPasswordStrength {
+    private static func passwordStrength(forEntropy entropy: Float) -> PasswordStrength {
         if entropy < 28 {
             return .veryWeak
         } else if entropy < 36 {

        }
    }

    private class func NJOEntropy(for string: String) -> Float {
        guard string.characters.count > 0 else {
            return 0.0
        }

    /// - parameter password: Password string to be calculated
    ///
    /// - returns: Level of strength in NJOPasswordStrength
    open static func strength(ofPassword password: String) -> PasswordStrength {
        return passwordStrength(forEntropy: entropy(of: password))
    }

    /// Converts NJOPasswordStrength to localized string.
