input: Write a function to create a Python dictionary to store data about a student. The dictionary should have keys 'name', 'year', 'gpa', 'courses', and 'extracurricular', with appropriate values for each key. If no input is provided, the default dictionary should contain the given student information.
  assert create_student_data() == {
      'name': 'John Smith',
      'year': 'Freshman',
      'gpa': 3.25,
      'courses': ['math', 'english', 'Computer Science', 'Statistics'],
      'extracurricular': ['Chess Club', 'Student Government', 'Debate Team']
  }
  assert create_student_data({'name': 'Alice Johnson', 'year': 'Sophomore', 'gpa': 3.5, 'courses': ['science', 'history'], 'extracurricular': []}) == {
      'name': 'Alice Johnson',
      'year': 'Sophomore',
      'gpa': 3.5,
      'courses': ['science', 'history'],
      'extracurricular': []
  }
  assert create_student_data({'name': 'Bob Brown', 'gpa': 3.0}) == {
      'name': 'Bob Brown',
      'year': 'Freshman',
      'gpa': 3.0,
      'courses': ['math', 'english', 'Computer Science', 'Statistics'],
      'extracurricular': ['Chess Club', 'Student Government', 'Debate Team']
  }
output: def create_student_data(data=None):
      default_data = {
          'name': 'John Smith',
          'year': 'Freshman',
          'gpa': 3.25,
          'courses': ['math', 'english', 'Computer Science', 'Statistics'],
          'extracurricular': ['Chess Club', 'Student Government', 'Debate Team']
      }
      if data is None:
          return default_data
      else:
          default_data.update(data)
          return default_data