https://blogs.sap.com/2015/01/05/abap-test-double-framework-an-introduction/
1: 创建接口ZIF_TD_CURRENCY_CONVER
2:添加,事件和方法
interface ZIF_TD_CURRENCY_CONVER public . EVENTS new_currency_code EXPORTING VALUE(currency_code) TYPE string. METHODS convert IMPORTING amount TYPE i source_currency TYPE string target_currency TYPE string RETURNING VALUE(result) TYPE i RAISING cx_td_currency_exception. METHODS convert_to_base_currency IMPORTING amount TYPE i source_currency TYPE string EXPORTING base_currency TYPE string base_curr_amount TYPE i. endinterface.
3:创建一个类
为该类创建测试类