FM SRT_TESTS_FB_SUM is "stateful". It increments and returns value of global variabe.
I created Web Service from this FM and set in Configuration parameter Stateful Communication = Stateful .
I try call this WS with SOAP UI. I copy set-cookie header (MYSAPSSO2) from first response and paste in Cookie header in second request. But return value is not increment. Call is stateless ...
set-cookie of first response:
MYSAPSSO2=Aj...(many symbols)...Du; path=/; domain=.<host>
I think MYSAPSSO2 used only for save pair user-password. But no session.
Perhaps here must be cookies: ap-appcontext,sap-contextid,JSESSIONID ?