set_param.rs

   pub fn set_param(&self, id: spa::param::ParamType, flags: u32, param: &[u8]) {
        unsafe {
            spa_interface_call_method!(
                self.proxy.as_ptr(),
                pw_sys::pw_node_methods,
                set_param,
                id.as_raw(),
                flags,
                param.as_ptr() as *const spa::sys::spa_pod
            );
        }