Function PSPropertyBag_WriteUnknown 

pub unsafe fn PSPropertyBag_WriteUnknown<P0, P1, P2>(
    propbag: P0,
    propname: P1,
    punk: P2,
) -> Result<()>
where
    P0: Param<IPropertyBag>,
    P1: Param<PCWSTR>,
    P2: Param<IUnknown>,