NullPointerException in Article.getReferences

[dansarie]

Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
        at java.base/java.util.ArrayList.<init>(ArrayList.java:179)
        at se.dansarie.jsnowball.model.Article.getReferences(Article.java:352)
        at se.dansarie.jsnowball.JSnowball$1.getEdges(JSnowball.java:112)
        at se.dansarie.jsnowball.JSnowball$1.getEdges(JSnowball.java:1)
        at se.dansarie.jsnowball.gui.GraphPanel.updateEdges(GraphPanel.java:105)
        at se.dansarie.jsnowball.gui.GraphPanel.updateNodes(GraphPanel.java:137)
        at se.dansarie.jsnowball.gui.GraphPanel.contentsChanged(GraphPanel.java:144)
        at se.dansarie.jsnowball.model.SnowballListModel.fireChanged(SnowballListModel.java:51)
        at se.dansarie.jsnowball.model.SnowballState.lambda$0(SnowballState.java:115)
        at java.desktop/java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:313)
        at java.desktop/java.awt.EventQueue.dispatchEventImpl(EventQueue.java:770)
        at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:721)
        at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:715)
        at java.base/java.security.AccessController.doPrivileged(Native Method)
        at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:85)
        at java.desktop/java.awt.EventQueue.dispatchEvent(EventQueue.java:740)
        at java.desktop/java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:203)
        at java.desktop/java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:124)
        at java.desktop/java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:113)
        at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:109)
        at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
        at java.desktop/java.awt.EventDispatchThread.run(EventDispatchThread.java:90)