Function object 

pub fn object(
    doc: &mut AutoCommit,
    parent: &ExId,
    key: &str,
    kind: ObjType,
) -> Option<ExId>

Construct a missing map or Text with one identity on every cold replica. Existing state is never replaced; a deleted canonical slot is never resurrected. Only identified records can use deterministic slots. None inside an action that already wrote: it makes the slot itself.