README.md in fluent-plugin-gcloud-pubsub-custom-1.3.1 vs README.md in fluent-plugin-gcloud-pubsub-custom-1.3.2

- old
+ new

@@ -131,11 +131,11 @@
   - You can also use environment variable such as `GCLOUD_PROJECT`.
 - `key` (optional)
   - Set your credential file path.
   - Running fluentd on GCP, you can use scope instead of specifying this.
   - You can also use environment variable such as `GCLOUD_KEYFILE`.
-- `topic` (required)
-  - Set topic name to pull.
+- `topic` (optional)
+  - Set topic name that the subscription belongs to.
 - `subscription` (required)
   - Set subscription name to pull.
 - `max_messages` (optional, default: `100`)
   - See maxMessages on https://cloud.google.com/pubsub/docs/reference/rest/v1/projects.subscriptions/pull
 - `return_immediately` (optional, default: `true`)