Remove unused SimpleXMLElement::children() method (#339)

src/Spout/Reader/Wrapper/SimpleXMLElement.php

@@ -149,22 +149,6 @@ class SimpleXMLElement
         return $doesElementExist ? $this->wrapSimpleXMLElement($realElement) : null;
     }
 
-    /**
-     * Returns the immediate children.
-     *
-     * @return SimpleXMLElement[] The children
-     */
-    public function children()
-    {
-        $children = [];
-
-        foreach ($this->simpleXMLElement->children() as $child) {
-            $children[] = $this->wrapSimpleXMLElement($child);
-        }
-
-        return $children;
-    }
-
     /**
      * @return string
      */