java.lang.NullPointerException: null

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via GitHub by rastating
, 2 years ago
Attempt to invoke interface method 'int java.util.List.size()' on a null object reference
via GitHub by oversecio
, 1 year ago
Attempt to invoke interface method 'int java.util.List.size()' on a null object reference
via google.com by Unknown author, 1 year ago
Attempt to invoke virtual method 'java.lang.Class java.lang.Object.getClass()' on a null object reference
java.lang.NullPointerException: null
at java.util.Collections.sort(Collections.java:175)
at com.vaadin.data.util.ContainerHierarchicalWrapper.updateHierarchicalWrapper(ContainerHierarchicalWrapper.java:191)
at com.vaadin.data.util.ContainerHierarchicalWrapper$PiggybackListener.containerItemSetChange(ContainerHierarchicalWrapper.java:838)
at com.vaadin.data.util.AbstractContainer.fireItemSetChange(AbstractContainer.java:242)
at com.vaadin.data.util.AbstractContainer.fireItemSetChange(AbstractContainer.java:228)
at com.vaadin.data.util.ContainerHierarchicalWrapper.fireItemSetChangeIfAbstractContainer(ContainerHierarchicalWrapper.java:506)
at com.vaadin.data.util.ContainerHierarchicalWrapper.setParent(ContainerHierarchicalWrapper.java:495)
at com.xinra.listaide.frontend.EstablishRelationWindow.lambda$3(EstablishRelationWindow.java:104)
at java.lang.Iterable.forEach(Iterable.java:75)
at com.xinra.listaide.frontend.EstablishRelationWindow.buildChildrenTree(EstablishRelationWindow.java:102)

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