input: def squared_values(numbers: List[int]) -> List[int]:
      """
      Generate a list of squared values using list comprehension.
      
      >>> squared_values([1, 2, 3, 5, 8, 13])
      [1, 4, 9, 25, 64, 169]
      """
output:     return [x ** 2 for x in numbers]