anchor.diff:  
               | Closed ->                          ()
   
  +        /// Dipose and remove a machine.
           let remove token =
               let machine = Map.find token machines
               (machine :> IDisposable).Dispose()
  
positive.code: 
              | Idle(_, _) ->                    ()
              
  
          /// Add a generic `IMachine<'c>` to the loop.
          /// 
          /// This can only be done if the loop is in the `Idle` state.
          member this.addMachine (f: EarlyScope -> 'a) =
              match loop with
              | Idle(loop, wakeup) -> let token = int64 machines.Count
                                      let scope = EarlyScope(token, loop, wakeup)
                                      let machine = f scope
  
                                      let machine = new Machine<'c>((machine :> IMachine<'c>), new UvTimerHandle())
                                      machines <- machines |> Map.add token machine
  
              | Closed ->             raise (NotImplementedException("Adding machines to dirty loops is not implemented"))
  
              | Running(_, _, _) ->   raise (NotImplementedException("Adding machines to running loops is not implemented"))
  
          /// Run the loop.
          /// 
  
negative.code:             match loop with
              | Idle(handle, wakeup) -> let memory = new MemoryPool()
                                        loop <- LoopState.Running(handle, wakeup, memory)
  
                                        init handle wakeup memory
  
                                        match machines.Count with
                                        | 0 -> 0
  