Added some wp function and Menu component

+<?php
+namespace Tz\WordPress\Tools\Menu;
+use Exception, Countable, Iterator;
+
+function get_nav_menu($location) {
+    $locations     = get_nav_menu_locations();
+    if (!isset($locations[$location])) {
+        throw new Exception("{$location} is not a defined menu location");
+    }
+    $menu_location = _get_nav_menu_object($locations[$location])->slug;
+    $menu = _get_nav_menu_items($menu_location);
+    _wp_menu_item_classes_by_context($menu);
+
+    return $menu;
+}
+
+
+class HierarchicalMenu implements Countable, Iterator {
+    private $contents = Array();
+    private $current  = 0;
+
+    private $id_lookup     = Array();
+    private $target_lookup = Array();
+
+    public function __construct(Array $menu, $parent = 0) {
+        $i = 0;
+        $last_id = -1;
+
+        foreach ($menu as $key => $item) {
+            $item->_children = false;
+
+            if ($item->menu_item_parent == $parent) {
+                $this->contents[$i] = $item;
+                $this->id_lookup[$item->ID] = $i;
+                $this->target_lookup[$item->object_id] = $i;
+
+                $i++;
+                $last_id = $item->ID;
+            } elseif ($item->menu_item_parent == $last_id) {
+                $this->contents[$this->id_lookup[$last_id]]->_children = true;
+            }
+        }
+
+        foreach ($this->contents as $key => $item) {
+            if (true === $item->_children) {
+                $item->HierarchicalMenu = new HierarchicalMenu($menu, $item->ID);
+            }
+            unset($this->contents[$key]->_children);
+        }
+    }
+
+    public function count() {
+        return count($this->contents);
+    }
+
+    public function current() {
+        return $this->contents[$this->current];
+    }
+
+    public function key() {
+        return $this->current;
+    }
+
+    public function next() {
+        $this->current++;
+    }
+
+    public function rewind() {
+        $this->rewind = 0;
+    }
+
+    public function valid() {
+        return (isset($this->contents[$this->current]) ? true : false);
+    }
+
+    public function getItemByID($id) {
+        return $this->id_lookup[$id] ?: false;
+    }
+
+    public function getItemByTarget($id) {
+        return $this->target_lookup[$id] ?: false;
+    }
+}
+?>
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@@ -180,4 +180,19 @@ function _nav_menu() {
     $params = func_get_args();
     return call_user_func_array('wp' . __FUNCTION__, $params);
 }
+
+function _get_nav_menu_object() {
+    $params = func_get_args();
+    return call_user_func_array('wp' . __FUNCTION__, $params);
+}
+
+function _get_nav_menu_items() {
+    $params = func_get_args();
+    return call_user_func_array('wp' . __FUNCTION__, $params);
+}
+
+function _reset_postdata() {
+    $params = func_get_args();
+    return call_user_func_array('wp' . __FUNCTION__, $params);
+}
 ?>
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