public final HttpAsyncClientBuilder setDefaultCookieStore(final CookieStore cookieStore) {
        this.cookieStore = cookieStore;
        return this;
    }
Sets default {@link CookieStore} instance which will be used for
request execution if not explicitly set in the client execution context.

@return this instance.
httpclient5/src/main/java/org/apache/hc/client5/http/impl/async/HttpAsyncClientBuilder.java