public void showHistory(final Collection<HistoryOsmPrimitive> primitives) {
List<HistoryOsmPrimitive> toLoad = filterPrimitivesWithUnloadedHistory(primitives);
if (!toLoad.isEmpty()) {
HistoryLoadTask task = new HistoryLoadTask(ChangesetContentPanel.this);
for (HistoryOsmPrimitive p: toLoad) {
task.add(p);
}
Main.worker.submit(task);
}
Main.worker.submit(new ShowHistoryTask(primitives));