@java.lang.Override
  public int getSerializedSize() {
    int size = memoizedSize;
    if (size != -1) return size;

    size = 0;
    if (((bitField0_ & 0x00000001) != 0)) {
      size += com.google.protobuf.CodedOutputStream.computeMessageSize(1, getSubscription());
    }
    if (validateOnly_ != false) {
      size += com.google.protobuf.CodedOutputStream.computeBoolSize(2, validateOnly_);
    }
    size += getUnknownFields().getSerializedSize();
    memoizedSize = size;
    return size;
  }
<pre>
Optional. If set to `true`, validates and previews the request, but doesn't
create the subscription.
</pre>

<code>bool validate_only = 2 [(.google.api.field_behavior) = OPTIONAL];</code>

@return The validateOnly.
java-workspaceevents/proto-google-cloud-workspaceevents-v1/src/main/java/com/google/apps/events/subscriptions/v1/CreateSubscriptionRequest.java