    - returns: A formatted string.
    */
   public static func wholeNumber(x: Int, env: Environment = AppEnvironment.current) -> String {
-    Format.wholeNumberFormatter.locale = env.locale
-    return Format.wholeNumberFormatter.stringFromNumber(x) ?? String(x)
+    let formatter = NumberFormatterConfig.cachedFormatter(
+      forConfig: .defaultWholeNumberConfig
+        |> NumberFormatterConfig.lens.locale .~ env.locale
+    )
+    return formatter.stringFromNumber(x) ?? String(x)
   }
 
   /**

                                       timeStyle: NSDateFormatterStyle = .MediumStyle,
                                       env: Environment = AppEnvironment.current) -> String {

    Format.dateFormatter.timeZone = env.timeZone
    Format.dateFormatter.locale = env.locale
    Format.dateFormatter.dateStyle = dateStyle
    Format.dateFormatter.timeStyle = timeStyle

    return Format.dateFormatter.stringFromDate(NSDate(timeIntervalSince1970: seconds))
  }

  /**

   - returns: A formatted string.
   */
  public static func percentage(percentage: Int, env: Environment = AppEnvironment.current) -> String {
    return Format.percentage(Double(percentage) / 100.0, env: env)
  }

  /**
