wrong access modifiers "private" instead of "protected"

In configuration is parameter:


  <parameter key="doctrine.orm.metadata.xml.class">Doctrine\ORM\Mapping\Driver\SimplifiedXmlDriver</parameter>


that suggest that is designed to override in private bundles but when you try to do that it's nessesary to repeat entire body of methods in own class because of "private" access modifiers, i suggest to change them to 'protected' because it's makes extendig this class more difficult and not clear to understand what is going on inside of this classes.

I suggest to change this modifiers not only in this class...