Function document 

pub fn document<'a, 'doc>(
    model: &'a mut Edits<'doc>,
    path: &'a (dyn Any + 'static),
) -> (&'a mut Edits<'doc>, &'a ExId)

The document and object a widget pass lent as its AppModel and ModelPath.

Panics

Panics if the host lent another model: a document runtime lends an AutoCommit and an ObjId in it.