Round tripping ADF documents

[Tim Penhey]

I'm wanting to programmatically update a Jira ticket's description.

The description is formatted using ADF, and I'm wanting to be able to scan the contents of the document for particular sub-elements.

The jsonschema for ADF references "localId", but this isn't really referenced in the ADF documentation (https://developer.atlassian.com/cloud/jira/platform/apis/document/structure/). Can I rely on this value being saved and echoed back? Is this use an expected and supported use of the `localId`?