Bug 319011 NPE when closing editor after closing a perspective
bundles/org.eclipse.e4.ui.workbench/src/org/eclipse/e4/ui/internal/workbench/ModelServiceImpl.java
boolean tbr = element.isToBeRendered();
		element.setOnTop(placeholder.isOnTop());
		element.setVisible(placeholder.isVisible());
		element.setToBeRendered(placeholder.isToBeRendered());
		placeholder.setOnTop(onTop);
		placeholder.setVisible(vis);
		placeholder.setToBeRendered(tbr);
		
		elementParent.getChildren().add(elementIndex, placeholder);
		phParent.getChildren().add(phIndex, element);
	}
	private void combine(MPartSashContainerElement toInsert, MPartSashContainerElement relTo,
			MPartSashContainer newSash, boolean newFirst, int ratio) {
		MElementContainer<MUIElement> curParent = relTo.getParent();
		int index = curParent.getChildren().indexOf(relTo);
		curParent.getChildren().remove(relTo);
		if (newFirst) {
			newSash.getChildren().add(toInsert);
			newSash.getChildren().add(relTo);
		} else {
			newSash.getChildren().add(relTo);
			newSash.getChildren().add(toInsert);
		}
		
		toInsert.setContainerData(Integer.toString(ratio));
		relTo.setContainerData(Integer.toString(100 - ratio));
		
		curParent.getChildren().add(index, newSash);
	}
	/*