      *  @playerversion AIR 2.0
      *  @productversion Flex 4.5
      */
-	public function setEstimatedSize(estimatedWidth:Number = NaN, 
-									 estimatedHeight:Number = NaN,
-									 invalidateSize:Boolean = true):void
+    public function setEstimatedSize(estimatedWidth:Number = NaN, 
+                                     estimatedHeight:Number = NaN,
+                                     invalidateSize:Boolean = true):void
     {
         
     }   

     * 
     *  The implementation calls <code>getElementBoundsAboveScrollRect()</code> and
     *  <code>getElementBoundsBelowScrollRect()</code> to determine the bounds of
     *  the elements.  Layout classes usually override those methods instead of
     *  getVerticalScrollPositionDelta(). 
     * 
     *  @see spark.core.NavigationUnit
     *  @see #getElementBoundsAboveScrollRect

    }
    
    /**
     *  Returns the change to the vertical scroll position to handle 
     *  different scrolling options. 
     *  These options are defined by the NavigationUnit class:
     *  <code>DOWN</code>,  <code>END</code>, <code>HOME</code>, 
