function createEventEnvelopeHeaders(
  event,
  sdkInfo,
  tunnel,
  dsn$1,
) {
  const dynamicSamplingContext = event.sdkProcessingMetadata && event.sdkProcessingMetadata.dynamicSamplingContext;
  return {
    event_id: event.event_id ,
    sent_at: new Date().toISOString(),
    ...(sdkInfo && { sdk: sdkInfo }),
    ...(!!tunnel && dsn$1 && { dsn: dsn.dsnToString(dsn$1) }),
    ...(dynamicSamplingContext && {
      trace: object.dropUndefinedKeys({ ...dynamicSamplingContext }),
    }),
  };
}
Creates event envelope headers, based on event, sdk info and tunnel
Note: This function was extracted from the core package to make it available in Replay