anchor.diff:                          [ opts.CustomClass ]
                           [ Classes.State.IsLoading, opts.IsLoading
                             Classes.HasIcon.Right, opts.HasIconRight
  -                          Classes.HasIcon.Left, opts.HasIconLeft ]
  +                          Classes.HasIcon.Left, opts.HasIconLeft
  +                          Classes.IsExpanded, opts.IsExpanded ]
   
           element (classes::opts.Props)
               children
  
positive.code:             | CustomClass customClass -> { result with CustomClass = customClass |> Some }
              | Props props -> { result with Props = props }
              | IsLoading state -> { result with IsLoading = state }
  
          let opts = options |> List.fold parseOptions Options.Empty
  
  
negative.code:           HasIconRight : bool
            CustomClass : string option
            Props : IHTMLProp list
            IsLoading : bool
            IsExpanded : bool }
          static member Empty =
              { HasIconLeft = false
                HasIconRight = false
                CustomClass = None
                Props = []
                IsLoading = false
                IsExpanded = false }
  
      let internal controlView element options children =
          let parseOptions (result : Options) =
  