code: public void end(String key)
      {
          if (key == null)
          {
              return;
          }
          TimingData data = executionInfo.get(key);
          if (data == null)
          {
              LOG.info("Called end with key: " + key + " without ever calling begin");
              return;
          }
          data.end();
      }
docs: Complete timing the operation with the given identifier. If you had not previously started a timing operation with this identifier, then this
  will effectively be a noop.