Method ~DebugLevelGuard

src/Tests/CoolProp-Tests.cpp:5153–5155

            int saved;
            DebugLevelGuard() : saved(CoolProp::get_debug_level()) {}
            ~DebugLevelGuard() {
                CoolProp::set_debug_level(saved);
            }
        } guard;
        CoolProp::set_debug_level(1);
        CHECK_THROWS_AS(CoolProp::add_fluids_as_JSON("PCSAFT", "this is not json"), CoolProp::ValueError);