OO ABAP - Use of SUPER keyword

*&---------------------------------------------------------------------*
*& Report  YSAP_CLASS_SUPER
*&
*&---------------------------------------------------------------------*
*&
*&
*&---------------------------------------------------------------------*

REPORT  ysap_class_super.


*----------------------------------------------------------------------*
*       CLASS class1 DEFINITION
*----------------------------------------------------------------------*
*
*----------------------------------------------------------------------*
CLASS class1 DEFINITION.
  PUBLIC SECTION.
    METHODS: constructor.
ENDCLASS.                    "class1 DEFINITION

*----------------------------------------------------------------------*
*       CLASS class1 IMPLEMENTATION
*----------------------------------------------------------------------*
*
*----------------------------------------------------------------------*
CLASS class1 IMPLEMENTATION.
  METHOD constructor.
    WRITE: / 'This is class1' COLOR 3.
  ENDMETHOD.                    "constructor
ENDCLASS.                    "class1 IMPLEMENTATION


*----------------------------------------------------------------------*
*       CLASS class2 DEFINITION
*----------------------------------------------------------------------*
*
*----------------------------------------------------------------------*
CLASS class2 DEFINITION INHERITING FROM class1.
  PUBLIC SECTION.
    METHODS: constructor.
ENDCLASS.                    "class2 DEFINITION

*----------------------------------------------------------------------*
*       CLASS class2 IMPLEMENTATION
*----------------------------------------------------------------------*
*
*----------------------------------------------------------------------*
CLASS class2 IMPLEMENTATION.
  METHOD constructor.
    CALL METHOD super->constructor.
    WRITE: / 'this is class2' COLOR 5.
  ENDMETHOD.                    "constructor
ENDCLASS.                    "class2 IMPLEMENTATION

*----------------------------------------------------------------------*
*       CLASS class3 DEFINITION
*----------------------------------------------------------------------*
*
*----------------------------------------------------------------------*
CLASS class3 DEFINITION INHERITING FROM class2.
  PUBLIC SECTION.
    METHODS: constructor.
ENDCLASS.                    "class3 DEFINITION

*----------------------------------------------------------------------*
*       CLASS class3 IMPLEMENTATION
*----------------------------------------------------------------------*
*
*----------------------------------------------------------------------*
CLASS class3 IMPLEMENTATION.
  METHOD constructor.
    CALL METHOD super->constructor.
    WRITE: / 'This is class3' COLOR 6.
  ENDMETHOD.                    "constructor
ENDCLASS.                    "class3 IMPLEMENTATION

START-OF-SELECTION.

  DATA: object1 TYPE REF TO class3.

  CREATE OBJECT object1.
 Output: