diff --git a/src/Entity/Channel.php b/src/Entity/Channel.php
new file mode 100644
index 0000000..176237e
--- /dev/null
+++ b/src/Entity/Channel.php
@@ -0,0 +1,31 @@
+<?php
+
+namespace Shikiryu\SRSS\Entity;
+
+use Shikiryu\SRSS\Entity\Channel\Image;
+
+class Channel
+{
+    public string $title;
+    public string $link;
+    public string $description;
+
+    public ?string $language;
+    public ?string $copyright;
+    public ?string $managingEditor;
+    public ?string $webMaster;
+    public ?string $pubDate;
+    public ?string $lastBuildDate;
+    public ?string $category;
+    public ?string $generator;
+    public ?string $docs;
+    public ?string $cloud;
+    public ?string $ttl;
+    public ?Image $image;
+    public ?string $rating;
+    public ?string $textInput;
+    public ?string $skipHours;
+    public ?string $skipDays;
+
+    public array $required = ['title', 'link', 'description'];
+}
\ No newline at end of file
diff --git a/src/Entity/Channel/Image.php b/src/Entity/Channel/Image.php
new file mode 100644
index 0000000..d794078
--- /dev/null
+++ b/src/Entity/Channel/Image.php
@@ -0,0 +1,15 @@
+<?php
+
+namespace Shikiryu\SRSS\Entity\Channel;
+
+class Image
+{
+    public string $url;
+    public string $title;
+    public string $link;
+    public int $width; // Maximum value for width is 144, default value is 88.
+    public int $height; //Maximum value for height is 400, default value is 31.
+    public string $description;
+
+    public array $required = ['url', 'title', 'link'];
+}
\ No newline at end of file
diff --git a/src/Entity/Item.php b/src/Entity/Item.php
new file mode 100644
index 0000000..a39ecc4
--- /dev/null
+++ b/src/Entity/Item.php
@@ -0,0 +1,19 @@
+<?php
+
+namespace Shikiryu\SRSS\Entity;
+
+class Item
+{
+    public ?string $title;
+    public ?string $link;
+    public ?string $description;
+    public ?string $author;
+    public ?string $category;
+    public ?string $comments;
+    public ?string $enclosure;
+    public ?string $guid;
+    public ?string $pubDate;
+    public ?string $source;
+
+    public array $required = ['description'];
+}
\ No newline at end of file
diff --git a/src/Media/Content.php b/src/Entity/Media/Content.php
similarity index 84%
rename from src/Media/Content.php
rename to src/Entity/Media/Content.php
index f518b53..05a045f 100644
--- a/src/Media/Content.php
+++ b/src/Entity/Media/Content.php
@@ -1,13 +1,14 @@
 <?php
 
-namespace Shikiryu\SRSS\Media;
+namespace Shikiryu\SRSS\Entity\Media;
 
+use DOMDocument;
 use DOMElement;
 use DOMNode;
 use Shikiryu\SRSS\SRSSException;
 use Shikiryu\SRSS\SRSSTools;
 
-class Content extends DOMElement
+class Content extends DomDocument
 {
     protected array $possibilities = [
         'url'          => 'link',
@@ -27,6 +28,8 @@ class Content extends DOMElement
     ];
     private array $attr = [];
 
+    private DOMNode $node;
+
     /**
      * Constructor
      *
@@ -34,16 +37,21 @@ class Content extends DOMElement
      */
     public function __construct(?\DOMNode $node = null)
     {
-        parent::__construct('media:content');
+        parent::__construct();
+        if ($node instanceof DOMElement) {
+            $this->node = $this->importNode($node, true);
+        } else {
+            $this->node = $this->importNode(new DomElement('item'));
+        }
         $this->_loadAttributes();
     }
 
     /**
      * @return void
      */
-    private function _loadAttributes()
+    private function _loadAttributes(): void
     {
-        foreach ($this->attributes as $attributes) {
+        foreach ($this->node->attributes as $attributes) {
             if (array_key_exists($attributes->name, $this->possibilities)) {
                 $this->{$attributes->name} = $attributes->value;
             }
@@ -102,8 +110,11 @@ class Content extends DOMElement
         }
 
         $flag = $this->possibilities[$name];
-        if ($flag !== '')
+
+        if ($flag !== '') {
             $val = SRSSTools::check($val, $flag);
+        }
+
         if (!empty($val)) {
             if ($this->$name === null) {
                 $this->node->appendChild(new DomElement($name, $val));
diff --git a/src/Entity/Media/Group.php b/src/Entity/Media/Group.php
new file mode 100644
index 0000000..64ca71c
--- /dev/null
+++ b/src/Entity/Media/Group.php
@@ -0,0 +1,8 @@
+<?php
+
+namespace Shikiryu\SRSS\Entity\Media;
+
+class Group
+{
+
+}
\ No newline at end of file
diff --git a/src/Media/Group.php b/src/Media/Group.php
deleted file mode 100644
index f096468..0000000
--- a/src/Media/Group.php
+++ /dev/null
@@ -1,8 +0,0 @@
-<?php
-
-namespace Shikiryu\SRSS\Media;
-
-class Group
-{
-
-}
\ No newline at end of file
diff --git a/src/SRSS.php b/src/SRSS.php
index ee940b2..9a4c164 100644
--- a/src/SRSS.php
+++ b/src/SRSS.php
@@ -3,16 +3,23 @@
 namespace Shikiryu\SRSS;
 
 use DOMDocument;
+use DOMNodeList;
 use DOMXPath;
 use Iterator;
+use ReturnTypeWillChange;
+use Shikiryu\SRSS\Entity\Channel;
+use Shikiryu\SRSS\Entity\Channel\Image;
+use Shikiryu\SRSS\Entity\Item;
 
 class SRSS extends DomDocument implements Iterator
 {
-    protected $xpath; // xpath engine
-    protected $items; // array of SRSSItems
+    protected DOMXPath $xpath; // xpath engine
+    protected array $items; // array of SRSSItems
     protected $attr; // array of RSS attributes
     private $position; // Iterator position
 
+    private Channel $channel;
+
     // lists of possible attributes for RSS
     protected $possibleAttr = [
         'title'				=> 'nohtml',
@@ -45,8 +52,8 @@ class SRSS extends DomDocument implements Iterator
         libxml_use_internal_errors(true);
         parent::__construct();
         $this->xpath = new DOMXpath($this);
-        $this->attr = array();
-        $this->items = array();
+        $this->attr = [];
+        $this->items = [];
         $this->position = 0;
         $this->formatOutput = true;
         $this->preserveWhiteSpace = false;
@@ -65,19 +72,19 @@ class SRSS extends DomDocument implements Iterator
     }
 
     /**
-     * @param $link string url of the rss
+     * @param string $link url of the rss
      * @throws SRSSException
      * @return SRSS
      */
-    public static function read($link): SRSS
+    public static function read(string $link): SRSS
     {
         $doc = new SRSS;
-        if(@$doc->load($link)) // We don't want the warning in case of bad XML. Let's manage it with an exception.
-        {
+        if(@$doc->load($link)) { // We don't want the warning in case of bad XML. Let's manage it with an exception.
             $channel = $doc->getElementsByTagName('channel');
             if($channel->length == 1){ // Good URL and good RSS
                 $doc->_loadAttributes(); // loading channel properties
                 $doc->getItems(); // loading all items
+
                 return $doc;
             }
 
@@ -89,6 +96,7 @@ class SRSS extends DomDocument implements Iterator
 
     /**
      * @return SRSS
+     * @throws \DOMException
      */
     public static function create()
     {
@@ -101,25 +109,31 @@ class SRSS extends DomDocument implements Iterator
         $doc->encoding = "UTF-8";
         $doc->generator = 'Shikiryu RSS';
         // $docs = 'http://www.scriptol.fr/rss/RSS-2.0.html';
+        $doc->channel = new Channel();
+        $doc->items = [];
+
         return $doc;
     }
 
     /**
      * getter of "image"'s channel attributes
      * @return string|array
+     * TODO
      */
     public function image()
     {
         $args = func_get_args();
-        if(func_num_args() == 0) $args[0] = 'url';
+        if (func_num_args() == 0) {
+            $args[0] = 'url';
+        }
         $img = $this->xpath->query('//channel/image');
-        if($img->length != 1) return null; // <image> is not in channel
+        if($img->length != 1) { // <image> is not in channel
+            return null;
+        }
         $img = $img->item(0);
-        $r = array();
-        foreach($img->childNodes as $child)
-        {
-            if($child->nodeType == XML_ELEMENT_NODE && in_array($child->nodeName, $args))
-            {
+        $r = [];
+        foreach($img->childNodes as $child) {
+            if($child->nodeType == XML_ELEMENT_NODE && in_array($child->nodeName, $args)) {
                 $r[$child->nodeName] = $child->nodeValue;
             }
         }
@@ -134,6 +148,7 @@ class SRSS extends DomDocument implements Iterator
      * @param $width int width
      * @param $height int height
      * @param $description string description
+     * TODO
      */
     public function setImage($url, $title, $link, $width = 0, $height = 0, $description = '')
     {
@@ -196,6 +211,7 @@ class SRSS extends DomDocument implements Iterator
      * @param $path string path
      * @param $registerProcedure string register procedure
      * @param $protocol string protocol
+     * TODO
      */
     public function setCloud($domain, $port, $path, $registerProcedure, $protocol)
     {
@@ -227,12 +243,13 @@ class SRSS extends DomDocument implements Iterator
     /**
      * check if current RSS is a valid one (based on specifications)
      * @return bool
+     * TODO use required
      */
     public function isValid()
     {
         $valid = true;
         $items = $this->getItems();
-        $invalidItems = array();
+        $invalidItems = [];
         $i = 1;
         foreach($items as $item){
             if($item->isValid() === false){
@@ -246,13 +263,16 @@ class SRSS extends DomDocument implements Iterator
 
     /**
      * getter of current RSS channel
-     * @return DOMElement
+     * @return \DOMNode
      * @throws SRSSException
      */
-    private function _getChannel()
+    private function _getChannel(): \DOMNode
     {
         $channel = $this->getElementsByTagName('channel');
-        if($channel->length != 1) throw new SRSSException('channel node not created, or too many channel nodes');
+        if($channel->length != 1) {
+            throw new SRSSException('channel node not created, or too many channel nodes');
+        }
+
         return $channel->item(0);
     }
 
@@ -298,16 +318,19 @@ class SRSS extends DomDocument implements Iterator
      */
     public function __get($name)
     {
-        if(isset($this->attr[$name]))
-            return $this->attr[$name];
+        if (isset($this->channel->{$name})) {
+            return $this->channel->{$name};
+        }
 //		$channel = $this->_getChannel();
         if(array_key_exists($name, $this->possibleAttr)){
             $tmp = $this->xpath->query('//channel/'.$name);
-            if($tmp->length != 1) return null;
+            if($tmp->length != 1) {
+                return null;
+            }
             return $tmp->item(0)->nodeValue;
-        }else{
-            throw new SRSSException($name.' is not a possible value.');
         }
+
+        throw new SRSSException($name.' is not a possible value.');
     }
 
     /**
@@ -357,71 +380,80 @@ class SRSS extends DomDocument implements Iterator
     /**
      * key from Iterator
      */
-    public  function key() {
+    #[ReturnTypeWillChange] public function key(): int
+    {
         return $this->position;
     }
 
     /**
      * next from Iterator
      */
-    public  function next() {
+    #[ReturnTypeWillChange] public function next(): void
+    {
         ++$this->position;
     }
 
     /**
      * valid from Iterator
      */
-    public  function valid() {
+    #[ReturnTypeWillChange] public function valid(): bool
+    {
         return isset($this->items[$this->position]);
     }
 
     /**
      * getter of 1st item
-     * @return SRSSItem
+     * @return Item
      */
-    public function getFirst()
+    public function getFirst(): ?Item
     {
         return $this->getItem(1);
     }
 
     /**
      * getter of last item
-     * @return SRSSItem
+     * @return Item
      */
-    public function getLast()
+    public function getLast(): Item
     {
         $items = $this->getItems();
-        return $items[count($items)-1];
+        return $items[array_key_last($items)];
     }
 
     /**
      * getter of an item
      * @param $i int
-     * @return SRSSItem
+     *
+     * @return Item|null
      */
-    public function getItem($i)
+    public function getItem(int $i): ?Item
     {
         $i--;
-        return isset($this->items[$i]) ? $this->items[$i] : null;
+        return $this->items[$i] ?? null;
     }
 
     /**
      * getter of all items
-     * @return SRSSItem[]
+     * @return Item[]
      * @throws SRSSException
      */
-    public function getItems()
+    public function getItems(): array
     {
+        if (!empty($this->items)) {
+            return $this->items;
+        }
+
         $channel = $this->_getChannel();
-        $item = $channel->getElementsByTagName('item');
-        $length = $item->length;
+        /** @var DOMNodeList $items */
+        $items = $channel->getElementsByTagName('item');
+        $length = $items->length;
         $this->items = [];
-        if($length > 0){
-            for($i = 0; $i < $length; $i++)
-            {
-                $this->items[$i] = new SRSSItem($item->item($i));
+        if ($length > 0) {
+            for($i = 0; $i < $length; $i++) {
+                $this->items[$i] = SRSSItem::read($items->item($i));
             }
         }
+
         return $this->items;
     }
 
@@ -429,31 +461,36 @@ class SRSS extends DomDocument implements Iterator
      * display XML
      * see DomDocument's docs
      */
-    public function show()
+    public function show(): bool|string
     {
+        // TODO build
         return $this->saveXml();
     }
 
 
     /**
      * putting all RSS attributes into the object
+     * @throws SRSSException
      */
-    private function _loadAttributes()
+    private function _loadAttributes(): void
     {
-        $channel = $this->_getChannel();
-        foreach($channel->childNodes as $child)
-        {
-            if($child->nodeType == XML_ELEMENT_NODE && $child->nodeName != 'item')
-            {
-                if($child->nodeName == 'image'){
-                    foreach($child->childNodes as $children)
-                    {
-                        if($children->nodeType == XML_ELEMENT_NODE)
-                            $this->attr['image'][$children->nodeName] = $children->nodeValue;
+        $node_channel = $this->_getChannel();
+        $this->channel = new Channel();
+
+        foreach($node_channel->childNodes as $child) {
+            if($child->nodeType == XML_ELEMENT_NODE && $child->nodeName !== 'item') {
+                if($child->nodeName == 'image') {
+                    $image = new Image();
+                    foreach($child->childNodes as $children) {
+                        if($children->nodeType == XML_ELEMENT_NODE) {
+                            $image->{$child->nodeName} = $children->nodeValue;
+                        }
                     }
+                    $this->channel->image = $image;
+
+                } else {
+                    $this->channel->{$child->nodeName} = $child->nodeValue;
                 }
-                else
-                    $this->attr[$child->nodeName] = $child->nodeValue;
             }
         }
     }
@@ -461,18 +498,16 @@ class SRSS extends DomDocument implements Iterator
     /**
      * transform current object into an array
      * @return array
+     * @throws SRSSException
      */
-    public function toArray()
+    public function toArray(): array
     {
-        $doc = array();
-        foreach($this->attr as $attrName => $attrVal)
-        {
-            $doc[$attrName] = $attrVal;
-        }
-        foreach($this->getItems() as $item)
-        {
+        $doc = $this->channel->toArray();
+
+        foreach($this->getItems() as $item) {
             $doc['items'][] = $item->toArray();
         }
+
         return $doc;
     }
 }
\ No newline at end of file
diff --git a/src/SRSSBuilder.php b/src/SRSSBuilder.php
new file mode 100644
index 0000000..6612563
--- /dev/null
+++ b/src/SRSSBuilder.php
@@ -0,0 +1,8 @@
+<?php
+
+namespace Shikiryu\SRSS;
+
+class SRSSBuilder
+{
+
+}
\ No newline at end of file
diff --git a/src/SRSSItem.php b/src/SRSSItem.php
index 09af81a..e940e19 100644
--- a/src/SRSSItem.php
+++ b/src/SRSSItem.php
@@ -4,18 +4,22 @@ namespace Shikiryu\SRSS;
 
 use DOMDocument;
 use DOMElement;
-use Shikiryu\SRSS\Media\Content;
+use DOMException;
+use DOMNode;
+use Shikiryu\SRSS\Entity\Item;
+use Shikiryu\SRSS\Entity\Media\Content;
 
+/**
+ * @property string|null $description
+ */
 class SRSSItem extends DomDocument
 {
-    /**
-     * @var DOMElement
-     */
-    protected $node; // item node
+
+    protected DOMNode $node; // item node
     protected $attr; // item's properties
 
     // possible properties' names
-    protected $possibilities = [
+    protected static $possibilities = [
         'title'         => 'nohtml',
         'link'          => 'link',
         'description'   => 'html',
@@ -38,44 +42,53 @@ class SRSSItem extends DomDocument
     public function __construct($node = null)
     {
         parent::__construct();
-        if ($node instanceof DOMElement) $this->node = $this->importNode($node, true);
-        else $this->node = $this->importNode(new DomElement('item'));
-        $this->_loadAttributes();
-    }
-
-    /**
-     * putting all item attributes into the object
-     */
-    private function _loadAttributes(): void
-    {
-        $this->_loadChildAttributes($this->node->childNodes);
+//        if ($node instanceof DOMElement) $this->node = $this->importNode($node, true);
+//        else $this->node = $this->importNode(new DomElement('item'));
+//        $this->_loadAttributes();
     }
 
     /**
+     * @param Item $item
      * @param $nodes
      *
      * @return void
      */
-    private function _loadChildAttributes($nodes): void
+    private static function _loadChildAttributes(Item $item, $nodes): void
     {
-        foreach ($nodes as $child) {
+        foreach ($nodes->childNodes as $child) {
             if ($child->nodeType === XML_ELEMENT_NODE && $child->nodeName !== 'item') {
-                if (array_key_exists($child->nodeName, $this->possibilities) && $this->possibilities[$child->nodeName] === 'folder') {
-                    $this->_loadChildAttributes($child->childNodes);
-                }
-                if  ($child->nodeName === 'media:content') {
-                    $this->{$child->nodeName} = new Content($child);
+                if (array_key_exists($child->nodeName, self::$possibilities) && self::$possibilities[$child->nodeName] === 'folder') {
+                    self::_loadChildAttributes($item, $child);
+                } elseif  ($child->nodeName === 'media:group') {
+                    // TODO
+                } elseif  ($child->nodeName === 'media:content') {
+                    $item->{$child->nodeName} = new Content($child);
                 } else {
-                    $this->{$child->nodeName} = $child->nodeValue;
+                    $item->{$child->nodeName} = $child->nodeValue;
                 }
             }
         }
     }
 
+    /**
+     * @param DOMNode|null $node
+     *
+     * @return Item
+     */
+    public static function read(?DOMNode $node = null): Item
+    {
+        $item = new Item();
+        if ($node instanceof DOMNode) {
+            self::_loadChildAttributes($item, $node);
+        }
+
+        return $item;
+    }
+
     /**
      * getter of item DomElement
      */
-    public function getItem()
+    public function getItem(): ?\DOMNode
     {
         $this->appendChild($this->node);
 
@@ -88,8 +101,9 @@ class SRSSItem extends DomDocument
      * @param $url    string url
      * @param $length int length
      * @param $type   string type
+     * @throws DOMException
      */
-    public function setEnclosure($url, $length, $type)
+    public function setEnclosure(string $url, int $length, string $type): void
     {
         $array = [];
         $url = SRSSTools::checkLink($url);
@@ -112,9 +126,9 @@ class SRSSItem extends DomDocument
      * check if current item is valid (following specifications)
      * @return bool
      */
-    public function isValid()
+    public function isValid(): bool
     {
-        return $this->description != null ? true : false;
+        return $this->description != null;
     }
 
     /**
@@ -133,7 +147,7 @@ class SRSSItem extends DomDocument
      * @param $name
      * @param $val
      *
-     * @throws SRSSException
+     * @throws SRSSException|DOMException
      */
     public function __set($name, $val)
     {
@@ -145,7 +159,9 @@ class SRSSItem extends DomDocument
         if ($flag !== '')
             $val = SRSSTools::check($val, $flag);
         if (!empty($val)) {
-            if ($this->$name == null) {
+            if ($val instanceof DOMElement) {
+                $this->node->appendChild($val);
+            } elseif ($this->$name == null) {
                 $this->node->appendChild(new DomElement($name, $val));
             }
             $this->attr[$name] = $val;
diff --git a/tests/BasicReader.php b/tests/BasicReader.php
index 36d9468..400eabb 100644
--- a/tests/BasicReader.php
+++ b/tests/BasicReader.php
@@ -11,6 +11,7 @@ class BasicReader extends TestCase
         $rss = SRSS::read(__DIR__.'/resources/basic.xml');
         self::assertEquals('test Home Page', $rss->title);
         $first_item = $rss->getFirst();
+        self::assertNotNull($first_item);
         self::assertEquals('RSS Tutorial', $first_item->title);
     }
 
diff --git a/tests/MediaTest.php b/tests/MediaTest.php
index fec2729..655f04f 100644
--- a/tests/MediaTest.php
+++ b/tests/MediaTest.php
@@ -13,6 +13,6 @@ class MediaTest extends TestCase
         $first_item = $rss->getFirst();
         self::assertEquals('Kirstie Alley, \'Cheers\' and \'Veronica\'s Closet\' star, dead at 71', $first_item->title);
 
-        self::assertEquals('https://cdn.cnn.com/cnnnext/dam/assets/221205172141-kirstie-alley-2005-super-169.jpg', $first_item->{'media:group'}->{'media:content'}->url);
+        self::assertEquals('https://cdn.cnn.com/cnnnext/dam/assets/221205172141-kirstie-alley-2005-super-169.jpg', $first_item->{'media:content'}->url);
     }
 }
\ No newline at end of file
diff --git a/tests/resources/harvard.xml b/tests/resources/harvard.xml
new file mode 100644
index 0000000..48dcb54
--- /dev/null
+++ b/tests/resources/harvard.xml
@@ -0,0 +1,41 @@
+<?xml version="1.0"?>
+<rss version="2.0">
+    <channel>
+        <title>Liftoff News</title>
+        <link>http://liftoff.msfc.nasa.gov/</link>
+        <description>Liftoff to Space Exploration.</description>
+        <language>en-us</language>
+        <pubDate>Tue, 10 Jun 2003 04:00:00 GMT</pubDate>
+        <lastBuildDate>Tue, 10 Jun 2003 09:41:01 GMT</lastBuildDate>
+        <docs>http://blogs.law.harvard.edu/tech/rss</docs>
+        <generator>Weblog Editor 2.0</generator>
+        <managingEditor>editor@example.com</managingEditor>
+        <webMaster>webmaster@example.com</webMaster>
+        <item>
+            <title>Star City</title>
+            <link>http://liftoff.msfc.nasa.gov/news/2003/news-starcity.asp</link>
+            <description>How do Americans get ready to work with Russians aboard the International Space Station? They take a crash course in culture, language and protocol at Russia's &lt;a href="http://howe.iki.rssi.ru/GCTC/gctc_e.htm"&gt;Star City&lt;/a&gt;.</description>
+            <pubDate>Tue, 03 Jun 2003 09:39:21 GMT</pubDate>
+            <guid>http://liftoff.msfc.nasa.gov/2003/06/03.html#item573</guid>
+        </item>
+        <item>
+            <description>Sky watchers in Europe, Asia, and parts of Alaska and Canada will experience a &lt;a href="http://science.nasa.gov/headlines/y2003/30may_solareclipse.htm"&gt;partial eclipse of the Sun&lt;/a&gt; on Saturday, May 31st.</description>
+            <pubDate>Fri, 30 May 2003 11:06:42 GMT</pubDate>
+            <guid>http://liftoff.msfc.nasa.gov/2003/05/30.html#item572</guid>
+        </item>
+        <item>
+            <title>The Engine That Does More</title>
+            <link>http://liftoff.msfc.nasa.gov/news/2003/news-VASIMR.asp</link>
+            <description>Before man travels to Mars, NASA hopes to design new engines that will let us fly through the Solar System more quickly.  The proposed VASIMR engine would do that.</description>
+            <pubDate>Tue, 27 May 2003 08:37:32 GMT</pubDate>
+            <guid>http://liftoff.msfc.nasa.gov/2003/05/27.html#item571</guid>
+        </item>
+        <item>
+            <title>Astronauts' Dirty Laundry</title>
+            <link>http://liftoff.msfc.nasa.gov/news/2003/news-laundry.asp</link>
+            <description>Compared to earlier spacecraft, the International Space Station has many luxuries, but laundry facilities are not one of them.  Instead, astronauts have other options.</description>
+            <pubDate>Tue, 20 May 2003 08:56:02 GMT</pubDate>
+            <guid>http://liftoff.msfc.nasa.gov/2003/05/20.html#item570</guid>
+        </item>
+    </channel>
+</rss>
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