private Event CreateStreamMetadataEvent()
 {
     var eventId = Guid.NewGuid();
     var acl = new StreamAcl(
         readRole: SystemRoles.Admins, writeRole: SystemRoles.Admins,
         deleteRole: SystemRoles.Admins, metaReadRole: SystemRoles.All,
         metaWriteRole: SystemRoles.Admins);
     var metadata = new StreamMetadata(maxCount: 2, maxAge: null, cacheControl: null, acl: acl);
     var dataBytes = metadata.ToJsonBytes();
     return new Event(eventId, SystemEventTypes.StreamMetadata, isJson: true, data: dataBytes, metadata: null);
 }
 private Event CreateStreamMetadataEvent(int? tb)
 {
     var eventId = Guid.NewGuid();
     var acl = new StreamAcl(
         readRole: SystemRoles.Admins, writeRole: SystemRoles.Admins,
         deleteRole: SystemRoles.Admins, metaReadRole: SystemRoles.Admins,
         metaWriteRole: SystemRoles.Admins);
     var metadata = new StreamMetadata(cacheControl: null, 
                                       truncateBefore: tb, 
                                       acl: acl);
     var dataBytes = metadata.ToJsonBytes();
     return new Event(eventId, SystemEventTypes.StreamMetadata, isJson: true, data: dataBytes, metadata: null);
 }