anchor.diff:  
           let changed = bunnyHillProjection.Change.Invoke(bh, systemContext, change)
   
  -        Assert.AreEqual(bh.DownrangeWindow.Start, changed.DownrangeWindow.Start)
  -        Assert.AreEqual(newWindowEnd, changed.DownrangeWindow.End)
  +        let actualWindow = changed.DownrangeWindow
  +        Assert.AreEqual<DownrangeWindow>(expectedWindow, actualWindow)
  
positive.code: 
          let changed = bunnyHillProjection.Change.Invoke(bh, systemContext, change)
  
          Assert.AreEqual(newWindowStart, changed.DownrangeWindow.Start)
          Assert.AreEqual(bh.DownrangeWindow.End, changed.DownrangeWindow.End)
  
      [<TestMethod>]
      member __.``Change window end`` () =
  
          let bh = { DownrangeWindow = { Start = 3.0<m>; End = 5.0<m> } }
          let newWindowEnd = bh.DownrangeWindow.End + 0.1<m>
          let change = ChangeWindowEnd newWindowEnd
          let systemContext = {
              SystemType = ArisSystemType.Aris3000
              WaterTemp = 20.0<degC>
  
negative.code:     [<TestMethod>]
      member __.``Change window start`` () =
  
          let initialStart, initialEnd = 3.0<m>, 5.0<m>
          let bh = { DownrangeWindow = { Start = initialStart; End = initialEnd } }
          let newWindowStart = initialStart + 0.1<m>
          let expectedWindow = { bh.DownrangeWindow with Start = newWindowStart }
          let change = ChangeWindowStart newWindowStart
          let systemContext = {
              SystemType = ArisSystemType.Aris3000
  