anchor.diff:  module Module =
     type Type() = class end
   """
  -  content |> shouldContainText "class=\"t\">Module</span>"
  -  content |> shouldContainText "class=\"t\">Type</span>"
  +  content |> shouldContainText (sprintf "class=\"%s\">Module</span>" CSS.Module)
  +  content |> shouldContainText (sprintf "class=\"%s\">Type</span>" CSS.ReferenceType)
   
   [<Test>]
   let ``Functions and methods are in spans of 'f' class``() = 
  
positive.code:         member __.Method x = ()
      let func2 x y = x + y
  """
    content |> shouldContainText "class=\"f\">func1</span>"
    content |> shouldContainText "class=\"f\">Method</span>"
    content |> shouldContainText "class=\"f\">func2</span>"
  
  [<Test>]
  let ``Printf formatters are in spans of 'pf' class``() = 
    let content = getContent """let _ = sprintf "a %A b %0.3fD" """
    content |> shouldContainText "class=\"s\">&quot;a </span>"
    content |> shouldContainText "class=\"pf\">%A</span>"
    content |> shouldContainText "class=\"s\"> b </span>"
    content |> shouldContainText "class=\"pf\">%0.3f</span>"
    content |> shouldContainText "class=\"s\">D&quot;</span>"
  
  [<Test>]
  let ``Escaped characters are in spans of 'e' class``() = 
    let content = getContent """let _ = sprintf "a \n\tD\uA0A0 \t" """
    content |> shouldContainText "class=\"s\">&quot;a </span>"
    content |> shouldContainText "class=\"e\">\\n</span>"
    content |> shouldContainText "class=\"e\">\\t</span>"
    content |> shouldContainText "class=\"s\">D</span>"
    content |> shouldContainText "class=\"e\">\\uA0A0</span>"
    content |> shouldContainText "class=\"s\"> </span>"
    content |> shouldContainText "class=\"e\">\\t</span>"
negative.code: 
  [<Test>]
  let ``Plain string is in span of 's' class when it's the last token in the line``() = 
    getContent """let _ = "str" """ |> shouldContainText <| sprintf "<span class=\"%s\">&quot;str&quot;</span>" CSS.String
  
  [<Test>]
  let ``Plain string is in span of 's' class, there are several other tokens next to it``() = 
    let content = getContent """let _ = "str", 1 """
    content |> shouldContainText <| sprintf "<span class=\"%s\">&quot;str&quot;</span>" CSS.String
    content |> shouldNotContainText <| sprintf  "<span class=\"%s\">,</span>" CSS.String
    content |> shouldContainText ","
  
  [<Test>]
  let ``Plain string is in span of 's' class, there is single char next to it``() = 
    let content = getContent """let _ = ("str")"""
    content |> shouldContainText "> (<"
    content |> shouldContainText <| sprintf  "<span class=\"%s\">&quot;str&quot;</span>" CSS.String
    content |> shouldContainText ">)"
  
  [<Test>]
  