INTERFACE {{p}}if_hire_fee PUBLIC.
  TYPES ty_amount TYPE p LENGTH 8 DECIMALS 2.
  TYPES:
    BEGIN OF ty_result,
      fee      TYPE ty_amount,
      discount TYPE ty_amount,
    END OF ty_result.
  METHODS calculate_fee
    IMPORTING iv_days          TYPE i
              iv_parts         TYPE i
              iv_express       TYPE abap_bool
    RETURNING VALUE(rs_result) TYPE ty_result.
ENDINTERFACE.