code: public JSONObject optJSONObject(int index) {
  		Object object = opt(index);
  		return object instanceof JSONObject ? (JSONObject) object : null;
  	}
docs: Returns the value at {@code index} if it exists and is a {@code
  JSONObject}. Returns null otherwise.
  @param index the index to get the value from
  @return the object at {@code index} or {@code null}