anchor.diff:      let C2 = 0x4cf5ad432745937fuL
   
       let inline rotateLeft (original : uint64) (bits : int) = 
  -        original <<< bits ||| original >>> (64 - bits)
  +        (original <<< bits) ||| (original >>> (64 - bits))
       let inline rotateRight (original : uint64) (bits : int) = 
  -        original >>> bits ||| original <<< (64 - bits)
  +        (original >>> bits) ||| (original <<< (64 - bits))
   
       let inline mixkey1 (k : uint64) =
           let mutable k = k
  
positive.code:         member __.Create () = new FNV1aStream(?bits = bits) :> HashStream
  
  /// 64-bit Fowler-Noll-Vo hashing algorithm
  and internal FNV1aStream (?bits : int) =
      inherit HashStream()
  
      let shift = 64 - (defaultArg bits 64)
  
negative.code:     interface IHashStreamFactory with
          member __.Create () = new MurMur3Stream(?seed = seed) :> HashStream
  
  and [<AutoSerializable(false)>]
    internal MurMur3Stream(?seed : uint64) =
      inherit HashStream()
  
      let mutable length = 0L
  