clear() public method

..
public clear ( )
 function clear()
 {
     foreach ($this->nodes as $n) {
         $n->clear();
         $n = null;
     }
     // This add next line is documented in the sourceforge repository. 2977248 as a fix for ongoing memory leaks that occur even with the use of clear.
     if (isset($this->children)) {
         foreach ($this->children as $n) {
             $n->clear();
             $n = null;
         }
     }
     if (isset($this->parent)) {
         $this->parent->clear();
         unset($this->parent);
     }
     if (isset($this->root)) {
         $this->root->clear();
         unset($this->root);
     }
     unset($this->doc);
     unset($this->noise);
 }