input: Write a function to create an object of type Student in Python containing relevant attributes. If the input is incomplete or missing, the function should return None.
  assert create_student("Alice", 20, "Female") == Student("Alice", 20, "Female")
  assert create_student("Bob", 22, "Male") == Student("Bob", 22, "Male")
  assert create_student("Charlie", 21) == None
  assert create_student("David") == None
  assert create_student() == None
output: def create_student(name=None, age=None, gender=None):
      if name is None or age is None or gender is None:
          return None
      return Student(name, age, gender)