anchor.diff:              let latestVer = con |> getLatestVersion entityId
               let newVer = latestVer + 1L
               if Option.isSome afterVersion && int64 afterVersion.Value <> latestVer then 
  -                raise (EntityConcurrencyException (entityId, sprintf "concurrency error while adding an event")) 
  +                raise (EntityConcurrencyException (sprintf "concurrency error while adding an event")) 
               else
               use cmd = new SqliteCommand("insert into EntityEvents (entityId, version, json) values (@eId,@eVer,@json)", con)
               cmd |> addParam ("@eId", Data.DbType.String, string entityId)
  
positive.code:     [<AutoOpen>]
      module internal Database =
  
          type Number   = int
          type Version  = int
          type JsonData = string
  
negative.code: 
      /// creates an event-repository using the given sqlite-connection-string
      /// this will check if a EntityEvents table exists and if not create one in the database
      let openAndCreate (conStr : string, useTransactions : bool) : IEventRepository<EntityId, 'event> =
          let con = new SqliteConnection (conStr)
          con |> createEntityEventsTable
          create (con, useTransactions)