input: 
  from typing import List
  
  def minimum_integer_value(ints: List[int]) -> int:
      """Given a list of integers, find and return the minimum integer value. If the list is empty, return None.
      >>> minimum_integer_value([3, 1, 4, 1, 5, 9, 2])
      1
      >>> minimum_integer_value([])
      None
      """
  
output:     if not ints:
          return None
      return min(ints)