docs: public static MarkdownNotebookOutput get(Object source) {
      try {
        StackTraceElement callingFrame = Thread.currentThread().getStackTrace()[2];
        String className = null == source ? callingFrame.getClassName() : source.getClass().getCanonicalName();
        String methodName = callingFrame.getMethodName();
        String fileName = methodName + ".md";
        File path = new File(Util.mkString(File.separator, "reports", className.replaceAll("\\.", "/").replaceAll("\\$", "/"), fileName));
        path.getParentFile().mkdirs();
        return new MarkdownNotebookOutput(path, methodName);
      } catch (FileNotFoundException e) {
        throw new RuntimeException(e);
      }
    }