code: public synchronized Object get(int index, Scriptable start) {
          Integer key = new Integer(index);
          if (indexedProps.containsKey(index)) {
              return indexedProps.get(key);
          } else {
              return NOT_FOUND;
          }            
      }
docs: Returns the value of the indexed property or NOT_FOUND.
  
  @param index the numeric index for the property
  @param start the object in which the lookup began
  @return the value of the property (may be null), or NOT_FOUND