amp/lib/MultiReasonException.php

<?php

namespace Amp;

class MultiReasonException extends \Exception {
    /** @var \Throwable[] */
    private $reasons;

    /**
     * @param \Throwable[] $reasons Array of exceptions rejecting the promise.
     * @param string|null $message
     */
    public function __construct(array $reasons, string $message = null) {
        parent::__construct($message ?: "Multiple errors encountered");

        $this->reasons = $reasons;
    }

    /**
     * @return \Throwable[]
     */
    public function getReasons(): array {
        return $this->reasons;
    }
}