mailgun-php/Mailgun/Guzzle/Plugin/Backoff/AbstractErrorCodeBackoffStrategy.php

<?php

namespace Guzzle\Plugin\Backoff;

/**
 * Strategy used to retry when certain error codes are encountered
 */
abstract class AbstractErrorCodeBackoffStrategy extends AbstractBackoffStrategy
{
    /** @var array Default cURL errors to retry */
    protected static $defaultErrorCodes = array();

    /** @var array Error codes that can be retried */
    protected $errorCodes;

    /**
     * @param array                    $codes Array of codes that should be retried
     * @param BackoffStrategyInterface $next  The optional next strategy
     */
    public function __construct(array $codes = null, BackoffStrategyInterface $next = null)
    {
        $this->errorCodes = array_fill_keys($codes ?: static::$defaultErrorCodes, 1);
        $this->next = $next;
    }

    /**
     * Get the default failure codes to retry
     *
     * @return array
     */
    public static function getDefaultFailureCodes()
    {
        return static::$defaultErrorCodes;
    }

    public function makesDecision()
    {
        return true;
    }
}