Defined in vss.d.ts
Data passed to the host from an extension frame via the initial handshake
notifyLoadSucceeded: boolean. If true, consider the extension loaded upon completion of the initial handshake.
extensionReusedCallback: (contribution: Contribution): void. Optional. Optional callback method that gets invoked when this extension frame is reused by another contribution which shares the same URI of the contribution that originally caused this extension frame to be loaded.