Here i recognized a problem, some tests and some situations are waiting for some exceptions and i have got no clue when catch an exception and just return null (or some equal) or doesn't catch it. So the `$session->getNode()` is done in try-catch blocks and without in several places. I tried to catch them in the getNodeForDocument() for example but got lots of red tests by that. Here we need to get aware when implementing persisters too.