Raise coverage

Author: tvdijen

tests/XMLSchema/XML/xs/ComplexContentTest.php

@@ -164,5 +164,7 @@ public function testMarshalling(): void
             self::$xmlRepresentation->saveXML(self::$xmlRepresentation->documentElement),
             strval($complexContent),
         );
+
+        $this->assertFalse($complexContent->isEmptyElement());
     }
 }