(core): serialize Composite with SessionWriter/SessionReader
Description
Proposal
(How you will do it)
Links / references
(Any references)
Documentation blurb
(Write the start of the documentation of this feature here, include:
- Why should someone use it; what's the underlying problem.
- What is the solution.
- How does someone use this
During implementation, this can then be copied and used as a starter for the documentation.)