### Question:
DefaultImportsEditorWidget extends ImportsEditorWidget<DefaultImport> { protected void loadServerDataTypes() { final Diagram diagram = sessionManager.getCurrentSession().getCanvasHandler().getDiagram(); final Path path = diagram.getMetadata().getPath(); dataTypeNamesService .call(path) .then(serverDataTypes -> { addDataTypes(serverDataTypes, true); return null; }) .catch_(exception -> { notification.fire(new NotificationEvent(StunnerFormsClientFieldsConstants.CONSTANTS.Error_retrieving_datatypes(), NotificationEvent.NotificationType.ERROR)); return null; }); } @Inject  DefaultImportsEditorWidget(final SessionManager sessionManager,
                                      final DataTypeNamesService dataTypeNamesService,
                                      final Event<NotificationEvent> notification); Map<String, String> getDataTypes(); String getDataType(String displayName); @Override DefaultImport createImport();  }### Answer:
@Test(expected = NullPointerException.class) public void loadServerDataTypes() { tested.dataTypes = new TreeMap<>(); tested.loadServerDataTypes(); verify(sessionManager, times(1)).getCurrentSession(); verify(session, times(1)).getCanvasHandler(); verify(canvasHandler, times(1)).getDiagram(); verify(diagram, times(1)).getMetadata(); verify(metadata, times(1)).getPath(); verify(dataTypeNamesService, times(1)).call(path); }