public Builder mergeApiKeyConfig(com.google.cloud.vertexai.api.ApiAuth.ApiKeyConfig value) {
      if (apiKeyConfigBuilder_ == null) {
        if (authConfigCase_ == 1
            && authConfig_
                != com.google.cloud.vertexai.api.ApiAuth.ApiKeyConfig.getDefaultInstance()) {
          authConfig_ =
              com.google.cloud.vertexai.api.ApiAuth.ApiKeyConfig.newBuilder(
                      (com.google.cloud.vertexai.api.ApiAuth.ApiKeyConfig) authConfig_)
                  .mergeFrom(value)
                  .buildPartial();
        } else {
          authConfig_ = value;
        }
        onChanged();
      } else {
        if (authConfigCase_ == 1) {
          apiKeyConfigBuilder_.mergeFrom(value);
        } else {
          apiKeyConfigBuilder_.setMessage(value);
        }
      }
      authConfigCase_ = 1;
      return this;
    }
<pre>
The API secret.
</pre>

<code>.google.cloud.vertexai.v1.ApiAuth.ApiKeyConfig api_key_config = 1;</code>
java-vertexai/proto-google-cloud-vertexai-v1/src/main/java/com/google/cloud/vertexai/api/ApiAuth.java