private void clearTempVariables(final String threadId) {
    final Map<String, Set<String>> threadVars = myTempVars.get(threadId);
    if (threadVars == null || threadVars.size() == 0) return;

    for (Map.Entry<String, Set<String>> entry : threadVars.entrySet()) {
      final Set<String> frameVars = entry.getValue();
      if (frameVars == null || frameVars.size() == 0) continue;

      final String expression = "del " + StringUtil.join(frameVars, ",");
      try {
        evaluate(threadId, entry.getKey(), expression, true);
      } catch (PyDebuggerException e) {
        LOG.error(e);
      }
    }

    myTempVars.clear(threadId);
  }