I have the following org-checkbox. 
```
Project 1
    [x] module 1
    [x] module 2
    [] module 3
    [x] module 4
```
How do i extract the checked values of `Project 1`
and pass the result to the code below?

```lisp
#+BEGIN_SRC elisp
    (json_print(module list)
#+END_SRC
```