User Todos documentation

[borndigital]

I am knowledge gathering via the documentation (https://canvas.instructure.com/doc/api/users.html#method.users.todo_items) and struggling to find answers to certain question by browsing and reading the documentation in-depth, searching in-page content, and can't see any info in the forums, so I'm asking questions here:

1. As per example API response, each example “todo” has a different object structure. What drives the object structure and can be “linked” to it?
   (can see “quiz” or “assignment”, are there others?)
2. As per example API response, what are the “type” values and what do they mean/describe?
   (can see “grading” or “submitting”, are there others?)
3. As per example API response, what are the “context_type” values and what do they mean/describe?
   (can see “course” or “group”, are there others?)
   
   Thanks