Optionalprovider: IMetadataProviderthe metadata provider to read and write through. Defaults to the global one.
Cancels the record's event in its calendar and marks the link Cancelled.
Creates the event in the target calendar (attendees get invitations) and links it to the record, storing the event's iCalendar UID so other calendars' copies can be matched to it.
Syncs one calendar: reads its changes since the stored token (a full sync of the window when there is none, or when the provider refuses it), applies them to the links they touch and to their records, and stores the new token only when every change was applied.
Changes the record's event in its calendar (attendees get the update) and refreshes the link.
Creates, changes and syncs calendar events tied to records. Stateless; server-side (it needs a context user).