test: addCourse in Administration class

src/test/java/org/example/AdministrationTest.java

@@ -72,4 +72,11 @@ class AdministrationTest {
         assertEquals(student, student2);
     }
 
+    @Test
+    void addCourse() {
+        Administration admin = new Administration();
+        Course course = new Course("Math", "M101", 4);
+        admin.addCourse(course);
+        assertEquals(course, admin.findCourseByID("M101"));
+    }
 }