input: Write a python function to find the student with the highest grade from a list of Student objects.
  assert find_top_student([Student("Alice", 90), Student("Bob", 85), Student("Charlie", 92)]).name == "Charlie"
  assert find_top_student([Student("Dave", 78), Student("Eve", 88), Student("Frank", 84)]).name == "Eve"
  assert find_top_student([Student("Grace", 70), Student("Heidi", 95), Student("Ivan", 95)]).name in ["Heidi", "Ivan"]
output: def find_top_student(students):
      return max(students, key=lambda student: student.grade)