columns.add(new TypePropertyColumn(new ResourceModel("type")).setInitialSize(80));
columns.add(new SizeColumn(new ResourceModel("size")).setInitialSize(100));
columns.add(new MimeTypeColumn(new ResourceModel("mimeType")).setInitialSize(80));
columns.add(new DatePropertyColumn(new ResourceModel("created"), "created", FolderDataSource.PROPERTY_CREATED)
.setInitialSize(120));
columns.add(new PropertyColumn(new ResourceModel("createdBy"), "createdBy",
FolderDataSource.PROPERTY_CREATED_BY).setInitialSize(90));
columns.add(new DatePropertyColumn(new ResourceModel("lastModified"), "lastModified",
FolderDataSource.PROPERTY_LAST_MODIFIED).setInitialSize(120));
columns.add(new PropertyColumn(new ResourceModel("lastModifiedBy"), "lastModifiedBy",
FolderDataSource.PROPERTY_LAST_MODIFIED_BY).setInitialSize(110));
FolderDataSource source = new FolderDataSource() {
@Override
BrixNode getFolderNode() {