code: function() {
              var nViewportOffset = Overlay.VIEWPORT_OFFSET,
                  element = this.element,
                  elementWidth = element.offsetWidth,
                  elementHeight = element.offsetHeight,
                  viewportWidth = Dom.getViewportWidth(),
                  viewportHeight = Dom.getViewportHeight();
  
              return ((elementWidth + nViewportOffset < viewportWidth) && (elementHeight + nViewportOffset < viewportHeight));
          }
docs: Determines if the Overlay (including the offset value defined by Overlay.VIEWPORT_OFFSET)
  will fit entirely inside the viewport, in both dimensions - width and height.
  
  @method fitsInViewport
  @return boolean true if the Overlay will fit, false if not