anchor.diff:              |> variance 
               |> shouldBe (fun v -> v <= 0.5)
   
  -            let original = partitionable.ToEnumerable() |> run |> Seq.toArray
  -            partitionss 
  +            let original = partitionable.ToEnumerable() |> run |> Seq.sum
  +            partitionss
               |> Seq.collect snd 
  -            |> Sequential.collect (fun p -> p.ToEnumerable()) 
  +            |> Sequential.map (fun p -> p.ToEnumerable())
               |> run
  +            |> Seq.concat
  +            |> Seq.sum
               |> shouldEqual original
   
           Check.QuickThrowOnFail(tester, maxRuns = fsCheckRetries)
  
positive.code:             |> shouldBe (fun v -> v <= 0.5)
  
              // test that partitions contain identical sequences to source
              let original = partitionables |> Sequential.collect (fun p -> p.ToEnumerable()) |> run
              partitionss 
              |> Seq.collect snd 
              |> Sequential.collect (fun p -> p.ToEnumerable()) 
              |> run
              |> shouldEqual original
  
          Check.QuickThrowOnFail(tester, maxRuns = fsCheckRetries)
  
negative.code:             sizes |> Array.sumBy snd |> shouldEqual (collectionSizes |> Array.sumBy (snd >> abs))
  
              // test that partitions contain identical sequences to source
              let original = collections |> Sequential.map (fun p -> p.ToEnumerable()) |> run |> Seq.concat |> Seq.sum
              partitionss 
              |> Seq.collect snd 
              |> Sequential.map (fun p -> p.ToEnumerable()) 
              |> run
              |> Seq.concat
              |> Seq.sum
              |> shouldEqual original
  
          Check.QuickThrowOnFail(tester, maxRuns = fsCheckRetries)