return null;
return createUnknown(className);
	public static SourceLineAnnotation fromVisitedInstructionRange(BetterVisitor visitor, int startPC, int endPC) {		LineNumberTable lineNumberTable = getLineNumberTable(visitor);		if (lineNumberTable == null)			return null;		int startLine = lineNumberTable.getSourceLine(startPC);		int endLine = lineNumberTable.getSourceLine(endPC);		return new SourceLineAnnotation(visitor.getBetterClassName(), startLine, endLine);	}