refactoring: extract sampleCourse in AdministrationTest file

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

@@ -6,6 +6,8 @@ import static org.junit.jupiter.api.Assertions.*;
 
 class AdministrationTest {
 
+    private static final Course sampleCourse = new Course("Math", "M101", 4);
+
     // Test the findProfessorById Method
     @Test
     void findProfessorById() {
@@ -79,7 +81,7 @@ class AdministrationTest {
     @Test
     void addCourse() {
         Administration admin = new Administration();
-        Course course = new Course("Math", "M101", 4);
+        Course course = sampleCourse;
         admin.addCourse(course);
         assertEquals(course, admin.findCourseByID("M101"));
     }
@@ -92,7 +94,7 @@ class AdministrationTest {
     public void testDeleteCourse() {
         Administration administration = new Administration();
         // Adding a course
-        Course course = new Course("Math", "M101", 4);
+        Course course = sampleCourse;
         administration.addCourse(course);
 
         // Deleting the course
@@ -110,7 +112,7 @@ class AdministrationTest {
     public void testFindCourseByID() {
         Administration administration = new Administration();
         // Adding a course
-        Course course = new Course("Math", "M101", 4);
+        Course course = sampleCourse;
         administration.addCourse(course);
 
         // Finding the added course