src/main/java/lecture_20_exams/corona/ICoronaData.java

src/main/java/lecture_20_exams/library/Book.java

src/main/java/lecture_20_exams/library/Library.java

src/main/java/lecture_20_exams/music/MusicSorter.java

src/main/java/lecture_20_exams/music/Song.java

src/main/java/lecture_20_exams/scrabble/Scrabble.java

src/main/java/lecture_20_exams/scrabble/ScrabbleTest.java