public Builder mergeApiKeyConfig(com.google.cloud.vertexai.api.ApiAuth.ApiKeyConfig value) {
        if (apiKeyConfigBuilder_ == null) {
          if (((bitField0_ & 0x00000002) != 0)
              && apiKeyConfig_ != null
              && apiKeyConfig_
                  != com.google.cloud.vertexai.api.ApiAuth.ApiKeyConfig.getDefaultInstance()) {
            getApiKeyConfigBuilder().mergeFrom(value);
          } else {
            apiKeyConfig_ = value;
          }
        } else {
          apiKeyConfigBuilder_.mergeFrom(value);
        }
        if (apiKeyConfig_ != null) {
          bitField0_ |= 0x00000002;
          onChanged();
        }
        return this;
      }
<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