             _hasThousandSeparators = newValue
         }
     }
-    
-    internal var _thousandSeparator: String!
+
+    private var _thousandSeparator: String!
     open var thousandSeparator: String! {
         get {
             return _thousandSeparator

            _zeroSymbol = newValue
        }
    }
    
    internal var _textAttributesForZero: [String : Any]?
    open var textAttributesForZero: [String : Any]? {
        get {
            return _textAttributesForZero

            _negativeInfinitySymbol = newValue
        }
    }

    private var _textAttributesForNegativeInfinity: [String : Any]?
    open var textAttributesForNegativeInfinity: [String : Any]? {
        get {
            return _textAttributesForNegativeInfinity
