anchor.diff:          | false -> fail (err)
       
       /// Take a Choice result and return true for Choice1 and false for Choice2
  -    let inline resultToBool result =
  +    let inline resultToBool result = 
           match result with
           | Choice1Of2(_) -> true
           | _ -> false
  -
  +    
       //    /// If the given result is a Success the wrapped value will be returned. 
       //    ///Otherwise the function throws an exception with Failure message of the result.
       //    let inline returnOrFail result = 
  
positive.code:         store.ObjectStore.TryRemove(key) |> ignore
          store.ObjectStore.TryAdd(key, value) |> ignore
          store.PersistenceStore.UpdateItem(key, metaData)
  
      ///  Add or update an item
      let inline updateMetaData (key, state, metaData : 'FlexMeta) (store : T<_, _, _>) = 
          let value = 
  
negative.code:         // get garbage collected.
          store.ObjectStore.TryAdd(key, value) |> ignore
          store.PersistenceStore.UpdateItem(key, metaData)
      
      /// Add or update an instance of an item
      let inline addInstance (key, state, metaData : 'FlexMeta, instance : 'LuceneObject) (store : T<_, _, _>) = 
          let value = 
              { MetaData = metaData
                State = state
  