function connectBlockLayerAndWithin($BlockRef, oWithinDOMRef) {
		if (oWithinDOMRef === window) {
			clearSizeAndPosition($BlockRef);
			document.documentElement.classList.add("sapUiBLyBack");
		} else {
			adaptSizeAndPosition($BlockRef, oWithinDOMRef);
			oWithinDOMRef.classList.add("sapUiBLyBack");
			oResizeObserver.observe(oWithinDOMRef);
		}
	}
Removes a previously attached event handler <code>fnFunction</code> from the static
{@link #.blockLayerStateChange blockLayerStateChange} event.

The event gets triggered in case of modal popups when the first of multiple popups opens and closes.

@param {function}
           fnFunction The function to be called, when the event occurs
@param {object}
           [oListener] Context object on which the given function had to be called

@public