After implementing the program above, I still get the error "java.lang.NumberFormatException: For input string: $"$id$"$

at java.base$/$java$.$lang.NumberFormatException.forInputString$($NumberFormatException$.$java:$67)$

at java.base$/$java$.$lang.Integer.parseInt$($Integer$.$java:$668)$

at java.base$/$java$.$lang.Integer.parseInt$($Integer$.$java:$786)$

at LastFMRecommender.loadArtists$($LastFMRecommender$.$java:$23)$

at LastFMRecommender.$($LastFMRecommender$.$java:$13)$

at LastFMRecommenderTest.testListFriends$($LastFMRecommenderTest$.$java:$9)$

at java.base$/$java$.$lang.reflect.Method.invoke$($Method$.$java:$568)$

at java.base$/$java$.$util.ArrayList.forEach$($ArrayList$.$java:$1511)$

at java.base$/$java$.$util.ArrayList.forEach$($ArrayList$.$java:$1511)"$

I tried different ID's and still get the same error. What is the issue here?