filteredContentProvider.addFilter(instanceOf(Duration.class));
viewer.setContentProvider(filteredContentProvider);
// Column sorters:
TreeViewerColumnSorter labelSorter =
new InternalTreeViewerColumnLabelSorter(viewer, mainLabels);
TreeViewerColumnSorter durationSorter =
new TreeViewerColumnValueSorter(viewer, durationProvider);
// The columns: