pub unsafe extern "system" fn SLActivateProduct(
    hslc: *const c_void,
    pproductskuid: *const GUID,
    cbappspecificdata: u32,
    pvappspecificdata: *const c_void,
    pactivationinfo: *const SL_ACTIVATION_INFO_HEADER,
    pwszproxyserver: PCWSTR,
    wproxyport: u16
) -> HRESULT