input: def generate_random_string(length: int) -> str:
      """Generate a random string of the specified length containing alphanumeric characters.
      >>> generate_random_string(8)
      'a1B2c3D4'
      >>> generate_random_string(8)
      'E5f6G7h8'
      """
      import string
      import random
      chars = string.ascii_letters + string.digits
      return ''.join(random.choice(chars) for _ in range(length))
output:     import string
      import random
      chars = string.ascii_letters + string.digits
      return ''.join(random.choice(chars) for _ in range(length))