Example of CakePHP Collection

collection.php

<?php
$countries = ['Denmark', 'Netherlands', 'France'];
$types = ['Italian', 'Japanese', 'Chinese'];

collection($countries)
    ->unfold(function ($country) use ($types) {
        foreach ($types as $type) {
            yield $country => $type;
    }
    })
    ->map(function ($type, $country) use ($yelpApi) {
        return $yelpApi->getPopularPlaces($country, $type);
    })
    ->filter(function ($result) {
        return empty($result['error']);
    })
    ->unfold(function ($result, $country) {
        foreach ($result['places'] as $place) {
            yield $country => $place;
        }
    })
    ->toList();