/// [`OptionalField`] simply gets `Present` if there are enough bytes to read into it), we have a
/// separate enum type for them.
///
-/// (C-not exported) due to a free generic in `T`
+/// This is not exported to bindings users due to a free generic in `T`
#[derive(Clone, Debug, PartialEq, Eq)]
pub enum OptionalField<T> {
/// Optional field is included in message