Batch inference cancel

<?php
require 'examples/boot.php';
require __DIR__.'/../Support/DemoBatch.php';

use Cognesy\Polyglot\BatchInference\Enums\BatchStatus;
use Examples\BatchInference\Support\DemoBatch;

$batches = DemoBatch::client();
$reference = $batches->submit(DemoBatch::items())->reference();
$receipt = $batches->cancel($reference);
$later = $batches->retrieve($reference);
$outcomes = iterator_to_array($batches->results($reference)->items());

if (!$receipt->acknowledged() || $receipt->alreadyTerminal()
    || $later->status() !== BatchStatus::Completed || count($outcomes) !== 2) {
    throw new RuntimeException('Cancellation race was not represented faithfully.');
}
echo "Cancellation acknowledged; later state completed with retained outcomes\n";
?>