public Builder clearEvent() {
      event_ = getDefaultInstance().getEvent();
      bitField0_ = (bitField0_ & ~0x00000004);
      onChanged();
      return this;
    }
<pre>
Optional. The name of the event. If unspecified, the thumbnail will be
retrieved from the latest event.
</pre>

<code>string event = 3 [(.google.api.field_behavior) = OPTIONAL];</code>

@return This builder for chaining.
java-visionai/proto-google-cloud-visionai-v1/src/main/java/com/google/cloud/visionai/v1/GetStreamThumbnailRequest.java