Handle notifications for all objects in com.nexmo.sdk.conversation.client for Events that have been completed.
||Generic event handler, responsible for handling
results of events created by user self.
||Common interface for dispatching events.
||Generic network exception.
||Nexmo API exception that can be caught and handled, encapsulates following information:
rid: Optional request id for which the error occurred, null if the request was pre-validated client side.