How to do it

Execute the recipe's file with your python interpreter.  It will run the following code:

util = URLUtility(const.ApodEclipseImage())
print(util.filename_without_ext)

This results in the following output:

Reading URL: https://apod.nasa.gov/apod/image/1709/BT5643s.jpg
Read 171014 bytes
The filename is: BT5643s