@Override
 protected void run()
     throws IOException, NoSuchTraceException, AlreadyExistsException, LoadTraceException {
   if (orig_trace_name != null) {
     Trace<?> orig_trace = orig_store.getTrace(orig_trace_name);
     Trace<?> dest_trace = dest_store.newTrace(dest_trace_name, orig_trace.type(), force);
     truncate(dest_trace, orig_trace);
   } else {
     for (Trace<?> orig_trace : orig_store.listTraces()) {
       Trace<?> dest_trace = dest_store.newTrace(orig_trace.name(), orig_trace.type(), force);
       truncate(dest_trace, orig_trace);
     }
   }
 }