Function files_hint 

pub fn files_hint(
    state: LifecycleState,
    locked_by: Option<Uuid>,
    me: Uuid,
    editable: bool,
    can_work: bool,
    can_revise: bool,
) -> FilesHint

editable: the user holds the check-out and may modify (the rule of ensure_editable); can_work: the user may check out (project group, role, revision in work, not locked by someone else).