conn_normalized = create_connection('normalized.db', True)
    create_table(conn_normalized, """CREATE TABLE IF NOT EXISTS [Degrees](Degree TEXT NOT NULL PRIMARY KEY);""")
    create_table(conn_normalized, """CREATE TABLE IF NOT EXISTS [Exams](Exam TEXT NOT NULL PRIMARY KEY, Year INT NOT NULL);""")
    create_table(conn_normalized, """CREATE TABLE IF NOT EXISTS [Students](StudentID INTEGER NOT NULL PRIMARY KEY, First_Name TEXT NOT NULL , Last_Name TEXT NOT NULL,Degree TEXT NOT NULL, FOREIGN KEY(Degree) REFERENCES Degrees(Degree));""")
    create_table(conn_normalized, """CREATE TABLE IF NOT EXISTS [StudentsExamScores](PK INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT ,StudentID INTEGER NOT NULL, Exam TEXT NOT NULL, Score INTEGER NOT NULL,FOREIGN KEY(StudentID) REFERENCES Students(StudentID), FOREIGN KEY(Exam) REFERENCES Exams(Exam));""")

    # fetch data from non-normalized database
    conn_non_normalized = create_connection(non_normalized_db_filename , False)
    degrees = set(row[0] for row in execute_sql_statement('''SELECT DISTINCT Degree FROM Students''', conn_non_normalized))
    exams = set((row[0], int(row[1])) for row in execute_sql_statement("""SELECT DISTINCT Exam, Year FROM Exams""", conn_non_normalized))
    students = [(id, first.strip(), last.strip(), degree) for id, name, degree in execute_sql_statement('''SELECT StudentID, Name, Degree FROM Students''', conn_non_normalized) for first, last in [name.split(',')]]
    scores = [s.strip().split(',') for row in execute_sql_statement('''SELECT Scores FROM Students''', conn_non_normalized) for s in row]
    students_scores = [(student_id, exam, int(score)) for student_id, student_scores in zip([row[0] for row in students], scores) for exam, score in zip([exam[0] for exam in exams], student_scores)]

    # insert data into normalized database
    with conn_normalized:
        [insert_degrees(conn_normalized, (degree,)) for degree in degrees]
        [insert_exams(conn_normalized, exam) for exam in exams]
        [insert_students(conn_normalized, student) for student in students]
        [insert_studentexamscores(conn_normalized, student_score) for student_score in students_scores]

    def insert_degrees(conn_normalized, values):
        sql = '''INSERT INTO Degrees(Degree) VALUES(?)'''
        cur = conn_normalized.cursor()
        cur.execute(sql, values)
        return cur.lastrowid

    def insert_exams(conn_normalized, values):
        sql = '''INSERT INTO Exams(Exam, Year) VALUES(?, ?)'''
        cur = conn_normalized.cursor()
        cur.execute(sql, values)
        return cur.lastrowid

    def insert_students(conn_normalized, values):
        sql = '''INSERT INTO Students(StudentID, First_Name, Last_Name, Degree) VALUES (?, ?, ?, ?)'''
        cur = conn_normalized.cursor()
        cur.execute(sql, values)
        return cur.lastrowid

    def insert_studentexamscores(conn_normalized, values):
        sql = '''INSERT INTO StudentsExamScores(StudentID, Exam, Score) VALUES (?, ?, ?)'''
        cur = conn_normalized.cursor()
        cur.execute(sql, values)
        return cur.lastrowid


the above code is giving following error:
Traceback (most recent call last):
  File "C:\Users\Tejesh Pawar\AppData\Local\Programs\Python\Python311\Lib\unittest\suite.py", line 166, in _handleClassSetUp
    setUpClass()
  File "C:\Users\Tejesh Pawar\Documents\Spring23\Python_ZIA\assignment6_test\tests\test_assignment.py", line 13, in setUpClass      
    assignment.normalize_database('non_normalized.db')
  File "c:\Users\Tejesh Pawar\Documents\Spring23\Python_ZIA\assignment6_test\assignment.py", line 468, in normalize_database        
    exams = set((row[0], int(row[1])) for row in execute_sql_statement("""SELECT DISTINCT Exam, Year FROM Exams""", conn_non_normalized))
                                                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "c:\Users\Tejesh Pawar\Documents\Spring23\Python_ZIA\assignment6_test\assignment.py", line 420, in execute_sql_statement     
    cur.execute(sql_statement)
sqlite3.OperationalError: no such table: Exams

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "c:\Users\Tejesh Pawar\Documents\Spring23\Python_ZIA\assignment6_test\run_tests.py", line 13, in <module>
    JSONTestRunner(visibility='visible', stream=f).run(suite)
  File "C:\Users\Tejesh Pawar\AppData\Local\Programs\Python\Python311\Lib\site-packages\gradescope_utils\autograder_utils\json_test_runner.py", line 196, in run
    test(result)
  File "C:\Users\Tejesh Pawar\AppData\Local\Programs\Python\Python311\Lib\unittest\suite.py", line 84, in __call__
    return self.run(*args, **kwds)
           ^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\Tejesh Pawar\AppData\Local\Programs\Python\Python311\Lib\unittest\suite.py", line 122, in run
    test(result)
  File "C:\Users\Tejesh Pawar\AppData\Local\Programs\Python\Python311\Lib\unittest\suite.py", line 84, in __call__
    return self.run(*args, **kwds)
           ^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\Tejesh Pawar\AppData\Local\Programs\Python\Python311\Lib\unittest\suite.py", line 122, in run
    test(result)
  File "C:\Users\Tejesh Pawar\AppData\Local\Programs\Python\Python311\Lib\unittest\suite.py", line 84, in __call__
    return self.run(*args, **kwds)
           ^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\Tejesh Pawar\AppData\Local\Programs\Python\Python311\Lib\unittest\suite.py", line 114, in run
    self._handleClassSetUp(test, result)
  File "C:\Users\Tejesh Pawar\AppData\Local\Programs\Python\Python311\Lib\unittest\suite.py", line 176, in _handleClassSetUp        
    self._createClassOrModuleLevelException(result, e,
  File "C:\Users\Tejesh Pawar\AppData\Local\Programs\Python\Python311\Lib\unittest\suite.py", line 236, in _createClassOrModuleLevelException
    self._addClassOrModuleLevelException(result, exc, errorName, info)
  File "C:\Users\Tejesh Pawar\AppData\Local\Programs\Python\Python311\Lib\unittest\suite.py", line 246, in _addClassOrModuleLevelException
    result.addError(error, sys.exc_info())
  File "C:\Users\Tejesh Pawar\AppData\Local\Programs\Python\Python311\Lib\site-packages\gradescope_utils\autograder_utils\json_test_runner.py", line 136, in addError
    self.processResult(test, err)
  File "C:\Users\Tejesh Pawar\AppData\Local\Programs\Python\Python311\Lib\site-packages\gradescope_utils\autograder_utils\json_test_runner.py", line 123, in processResult
    if self.getLeaderboardData(test)[0]:
       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\Tejesh Pawar\AppData\Local\Programs\Python\Python311\Lib\site-packages\gradescope_utils\autograder_utils\json_test_runner.py", line 51, in getLeaderboardData
    column_name = getattr(getattr(test, test._testMethodName), '__leaderboard_column__', None)
                                        ^^^^^^^^^^^^^^^^^^^^
AttributeError: '_ErrorHolder' object has no attribute '_testMethodName'

please fix it and send the updated one