public Builder setEvent(java.lang.String value) {
      if (value == null) {
        throw new NullPointerException();
      }
      event_ = value;
      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>

@param value The event to set.
@return This builder for chaining.
java-visionai/proto-google-cloud-visionai-v1/src/main/java/com/google/cloud/visionai/v1/GetStreamThumbnailRequest.java