invoke
inline operator fun <C : ExtensibleEventContent<ExtensibleEventContent.Legacy.None>> invoke(crossinline contentFactory: (blocks: EventContentBlocks) -> C): ExtensibleEventContentSerializer<ExtensibleEventContent.Legacy.None, C>
inline operator fun <L : ExtensibleEventContent.Legacy, C : ExtensibleEventContent<L>> invoke(noinline contentFactory: (blocks: EventContentBlocks, legacy: L?) -> C): ExtensibleEventContentSerializer<L, C>