@Override
        public void run() {
            try {
                final Response response = this.executor.execute(this.request);
                final T result = response.handleResponse(this.handler);
                this.future.completed(result);
            } catch (final Exception ex) {
                this.future.failed(ex);
            }
        }
Asynchronous executor for {@link Request}s.

@since 4.3
httpclient5-fluent/src/main/java/org/apache/hc/client5/http/fluent/Async.java