anchor.diff:              AuxLens = AuxLensType.None
               AntialiasingPeriod = 0<Us>
           }
  +
           let constrained = bunnyHillProjection.Constrain.Invoke(bh, ctx)
   
           Assert.AreNotEqual<BunnyHillSettings>(bh, constrained, "Must show *some* constraint!")
  
positive.code: 
          let changed = bunnyHillProjection.Change.Invoke(bh, systemContext, change)
  
          Assert.AreEqual(bh.DownrangeWindow.Start, changed.DownrangeWindow.Start)
          Assert.AreEqual(newWindowEnd, changed.DownrangeWindow.End)
  
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
  