small edit

codex-rs/core/src/codex.rs

@@ -2810,15 +2810,7 @@ async fn drain_to_completed(
                 response_id: _,
                 token_usage,
             }) => {
-                let token_usage = match token_usage {
-                    Some(usage) => usage,
-                    None => {
-                        return Err(CodexErr::Stream(
-                            "token_usage was None in ResponseEvent::Completed".into(),
-                            None,
-                        ));
-                    }
-                };
+                let token_usage = token_usage.unwrap_or_default();
                 sess.tx_event
                     .send(Event {
                         id: sub_id.to_string(),
@@ -2826,6 +2818,7 @@ async fn drain_to_completed(
                     })
                     .await
                     .ok();
+
                 return Ok(());
             }
             Ok(_) => continue,