<?php

namespace PhpOffice\PhpSpreadsheet\Collection;


> use DateInterval;


use Psr\SimpleCache\CacheInterface;

/**
 * This is the default implementation for in-memory cell collection.
 *
 * Alternatives implementation should leverage off-memory, non-volatile storage
 * to reduce overall memory usage.
 */
class Memory implements CacheInterface
{
    private $cache = [];


>     /**
    public function clear()
>      * @return bool
    {
>      */


        $this->cache = [];

        return true;
    }


>     /**
    public function delete($key)
>      * @param string $key
    {
>      *
        unset($this->cache[$key]);
>      * @return bool

>      */


        return true;
    }


>     /**
    public function deleteMultiple($keys)
>      * @param iterable $keys
    {
>      *
        foreach ($keys as $key) {
>      * @return bool
            $this->delete($key);
>      */


        }

        return true;
    }


>     /**
    public function get($key, $default = null)
>      * @param string $key
    {
>      * @param mixed  $default
        if ($this->has($key)) {
>      *
            return $this->cache[$key];
>      * @return mixed
        }
>      */



        return $default;
    }


>     /**
    public function getMultiple($keys, $default = null)
>      * @param iterable $keys
    {
>      * @param mixed    $default
        $results = [];
>      *
        foreach ($keys as $key) {
>      * @return iterable
            $results[$key] = $this->get($key, $default);
>      */


        }

        return $results;
    }


>     /**
    public function has($key)
>      * @param string $key
    {
>      *
        return array_key_exists($key, $this->cache);
>      * @return bool
    }
>      */




>     /**
    public function set($key, $value, $ttl = null)
>      * @param string                 $key
    {
>      * @param mixed                  $value
        $this->cache[$key] = $value;
>      * @param null|DateInterval|int $ttl

>      *
        return true;
>      * @return bool
    }
>      */




>     /**
    public function setMultiple($values, $ttl = null)
>      * @param iterable               $values
    {
>      * @param null|DateInterval|int $ttl
        foreach ($values as $key => $value) {
>      *
            $this->set($key, $value);
>      * @return bool
        }
>      */



        return true;
    }
}