code: public List<Entry> get (Name username)
      {
          List<Entry> history = getList(username);
          if (history != null) {
              prune(System.currentTimeMillis(), history);
          }
          return history;
      }
docs: Returns a list of {@link Entry} objects, one for each message to which this user has been
  privy in the recent past.  If the given name implements {@link KeepNoHistory}, null is
  returned.