CLASS lcl_test IMPLEMENTATION.
  METHOD m_sum.
    DATA: o_cut TYPE REF TO lcl_sum.
    DATA: lv_result TYPE i.
*
    CREATE OBJECT o_cut.
    lv_result = o_cut->sum( 3 ).
*
    cl_aunit_assert=>assert_equals(
        EXP                  = 6
        act                  = lv_result
        msg                  = 'something wrong'
           ).
  ENDMETHOD.                    "m_sum
ENDCLASS.                    "lcl_test IMPLEMENTATION