add skip serialization for opt value
@@ -22,6 +22,7 @@ pub struct RestrictChatMember<'a> {
///Date when restrictions will be lifted for the user, unix time. If user
/// is restricted for more than 366 days or less than 30 seconds from the
/// current time, they are considered to be restricted forever
+ #[serde(skip_serializing_if = "Option::is_none")]
pub until_date: Option<u64>,
}
