Reflow.

Signed-off-by: Chris Lamb <chris@thread.com>
Manual pass-through for save (for next commit)

Signed-off-by: Chris Lamb <chris@thread.com>
Manual pass-through for .exists()  (for next commit)

Signed-off-by: Chris Lamb <chris@thread.com>
Add support for an 'exists' field.

Signed-off-by: Chris Lamb <chris@thread.com>