anchor.diff:          let input = "<one/><two/><three/><four/>"
           let index, value, t = eatAt input 12
           value |> should equal "three"
  -        index |> should equal 19
  +        index |> should equal 20
           t |> should equal TagType.Single
   
       [<Test>]
  
positive.code:         let input = "<testTag />"
          let index, value, t = eat input
          value |> should equal "testTag"
          index |> should equal 10
          t |> should equal TagType.Single
  
  
  
negative.code:         let input = "< fooBar /> < testTag />"
          let index, value, t = eatAt input 10
          value |> should equal "testTag"
          index |> should equal 24
          t |> should equal TagType.Single
  
      [<Test>]
  