Runs the test case.
Document doc;
NodeList elementList;
Node employeeNode;
Node lcNode;
Node nsNode;
doc = (Document) load("staff", false);
elementList = doc.getElementsByTagName("employee");
employeeNode = elementList.item(1);
lcNode = employeeNode.getLastChild();
nsNode = lcNode.getNextSibling();
assertNull("nodeGetNextSiblingNullAssert1", nsNode);