public Builder clearEventTypes() {
      eventTypes_ = com.google.protobuf.LazyStringArrayList.emptyList();
      bitField0_ = (bitField0_ & ~0x00000020);
      ;
      onChanged();
      return this;
    }
<pre>
Required. Immutable. Unordered list. Input for creating a subscription.
Otherwise, output only. One or more types of events to receive about the
target resource. Formatted according to the CloudEvents specification.

The supported event types depend on the target resource of your
subscription. For details, see [Supported Google Workspace
events](https://developers.google.com/workspace/events/guides#supported-events).

By default, you also receive events about the [lifecycle of your
subscription](https://developers.google.com/workspace/events/guides/events-lifecycle).
You don't need to specify lifecycle events for this field.

If you specify an event type that doesn't exist for the target resource,
the request returns an HTTP `400 Bad Request` status code.
</pre>

<code>
repeated string event_types = 5 [(.google.api.field_behavior) = REQUIRED, (.google.api.field_behavior) = UNORDERED_LIST, (.google.api.field_behavior) = IMMUTABLE];
</code>

@return This builder for chaining.
java-workspaceevents/proto-google-cloud-workspaceevents-v1/src/main/java/com/google/apps/events/subscriptions/v1/Subscription.java