add duplicate items.

$3-$ Write code to ask the user for the path of the data file, read the file name, open the file, read

the file line by line, and upload the data to an SortedSet.

$4-$ Print the list. Make sure the items are in sorted order and there are no duplicates.

$5-$ Include at least two test cases for each one of the following methods: indexOf, remove,

grab, and categorySet. Make sure to print appropriate messages in the output so

that it is easy to interpret your test cases