if (offset < 1 || offset >= document.getLength()) return null;
	private static IRegion getSurroundingBlock(IDocument document, int offset) {		int begin= searchForOpeningPeer(document, offset - 1, '{', '}');		int end= searchForClosingPeer(document, offset, '{', '}');		if (begin == -1 || end == -1)			return null;		return new Region(begin, end + 1 - begin);	}