<?php

use Retry\RetryProxy;
use Retry\Policy\SimpleRetryPolicy;
use Retry\BackOff\ExponentialBackOffPolicy;

$retryPolicy = new SimpleRetryPolicy(3);
$backOffPolicy = new ExponentialBackOffPolicy();

$proxy = new RetryProxy($retryPolicy, $backOffPolicy);
$result = $proxy->call(function() {
    // call external service and return result
});