Remove commented code

We're not going to use it

lib/SimpleSAML/Compat/SspContainer.php

@@ -112,44 +112,4 @@ class SspContainer extends AbstractContainer
         }
         $sysUtils->writeFile($filename, $data, $mode);
     }
-
-
-    /**
-     * @inheritDoc
-    public function registerExtensionHandler(string $class): void
-    {
-        Assert::subclassOf($class, AbstractXMLElement::class);
-
-        if (is_subclass_of($class, CustomIdentifierInterface::class, true)) {
-            $key = $class::getXsiType() . ':BaseID';
-        } else {
-            $key = join(':', [urlencode($class::NS), AbstractXMLElement::getClassName($class)]);
-        }
-        $this->registry[$key] = $class;
-    }
-     */
-
-
-    /**
-     * @inheritDoc
-    public function getElementHandler(string $namespace, string $element): ?string
-    {
-        Assert::notEmpty($namespace, 'Cannot search for handlers without an associated namespace URI.');
-        Assert::notEmpty($element, 'Cannot search for handlers without an associated element name.');
-
-        return $this->registry[join(':', [urlencode($namespace), $element])];
-    }
-     */
-
-
-    /**
-     * @inheritDoc
-    public function getIdentifierHandler(string $type): ?string
-    {
-        Assert::notEmpty($type, 'Cannot search for identifier handlers with an empty type.');
-
-        $handler = $type . ':BaseID';
-        return array_key_exists($handler, $this->registry) ? $this->registry[$handler] : null;
-    }
-     */
 }