anchor.diff:      "TODO: crutch, redo later after unification
       REPLACE FIRST OCCURRENCE OF '</style>' IN lv_html
         WITH '</style>' && styles( )->mv_html.
  -
  -    "TODO: crutch, move to SAP back button (code almost ready)
  -    lv_html = lv_html && '<div>' && '<a href="sapevent:back">Back</a>' && '</div>'.
       ro_html->add( lv_html ).
   * ^^^ REDO
   
  
positive.code:   ENDMETHOD.
  
  ENDCLASS.
  AT SELECTION-SCREEN ON EXIT-COMMAND.
    CASE sy-ucomm.
      WHEN 'CBAC'.  "Back
  
negative.code:   METHOD lif_gui_page~on_event.
  
      CASE iv_action.
        WHEN OTHERS.
          _raise 'Unknown action'.                            "#EC NOTEXT
      ENDCASE.
  