code: public double getDouble(int index) throws JSONException {
  		Object object = get(index);
  		Double result = JSON.toDouble(object);
  		if (result == null) {
  			throw JSON.typeMismatch(index, object, "double");
  		}
  		return result;
  	}
docs: Returns the value at {@code index} if it exists and is a double or can be coerced
  to a double.
  @param index the index to get the value from
  @return the {@code value}
  @throws JSONException if the value at {@code index} doesn't exist or cannot be
  coerced to a double.