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

      size = 0;
      for (int i = 0; i < channels_.size(); i++) {
        size += com.google.protobuf.CodedOutputStream.computeMessageSize(1, channels_.get(i));
      }
      if (((bitField0_ & 0x00000001) != 0)) {
        size += com.google.protobuf.CodedOutputStream.computeMessageSize(3, getApiKeyConfig());
      }
      size += getUnknownFields().getSerializedSize();
      memoizedSize = size;
      return size;
    }
<pre>
Required. The SecretManager secret version resource name (e.g.
projects/{project}/secrets/{secret}/versions/{version}) storing the
Slack channel access token that has access to the slack channel IDs.
See: https://api.slack.com/tutorials/tracks/getting-a-token.
</pre>

<code>
.google.cloud.vertexai.v1.ApiAuth.ApiKeyConfig api_key_config = 3 [(.google.api.field_behavior) = REQUIRED];
</code>
java-vertexai/proto-google-cloud-vertexai-v1/src/main/java/com/google/cloud/vertexai/api/SlackSource.java