subprojects/parseq-http-client/src/main/java/com/linkedin/parseq/httpclient/HttpClient.java
@SuppressWarnings("resource")
  public static synchronized void initialize(AsyncHttpClientConfig cfg) {
    if (!_client.compareAndSet(null, new AsyncHttpClient(cfg))) {
      throw new RuntimeException("async http client concurrently initialized");
    }
  }
@SuppressWarnings("resource")
  public static synchronized void initialize(AsyncHttpClientConfig cfg) {
    if (!_client.compareAndSet(null, new AsyncHttpClient(cfg))) {
      throw new RuntimeException("async http client concurrently initialized");
    }
  }
Initializes HttpClient with custom configuration.
@param cfg client configuration
@see AsyncHttpClientConfig