anchor.diff:  
       member this.System = system
       member this.System2 = system2
  +
  +    member this.Contains entityId =
  +        cache.ContainsKey entityId
   
       member this.Iterate (fn : Statement<'c, 'c2, 's>) state =
           let array = system.Correlateds.Array
  
positive.code:     member this.System = system
      member this.System2 = system2
      member this.System3 = system3
      
      member this.Iterate (fn : Statement<'c, 'c2, 'c3, 's>) state =
          let array = system.Correlateds.Array
  
negative.code:     member this.System5 = system5
      member this.System6 = system6
      member this.System7 = system7
  
      member this.Contains entityId =
          cache.ContainsKey entityId
      
      member this.Iterate (fn : Statement<'c, 'c2, 'c3, 'c4, 'c5, 'c6, 'c7, 's>) state =
          let array = system.Correlateds.Array
  