input: Write a python function to get a list of students with a specific grade.
  assert get_students_with_grade(student_grades, "A") == ["Bob", "Alice"]
  assert get_students_with_grade(student_grades, "B") == ["Carol"]
  assert get_students_with_grade(student_grades, "C") == ["Ted"]
output: def get_students_with_grade(student_grades, grade):
      return [student for student, student_grade in student_grades.items() if student_grade == grade]