code: boolean isEmpty()
    {
      if (tc.isEntryEnabled())
        tc.entry(this,cclass, "isEmpty");
  
      boolean manyChildResult = singleMatchManyChild == null && 
                                  (matchManyChildren == null || matchManyChildren.isEmpty());
      boolean result = manyChildResult && matchOneChild == null && 
        exactChild == null && suffix == null;
  
      if (tc.isEntryEnabled())
        tc.exit(this,cclass, "isEmpty", "result: " + new Boolean(result));
  
      return result;
    }
docs: Tests for emptiness.  The anchor (keylen == 0) is never considered empty