input: def get_max_value(numbers):
      """
      This function takes a list of numbers and returns the largest value from the list.
      
      >>> get_max_value([2, 4, 1, 6])
      6
      >>> get_max_value([0, -5, 7, 3])
      7
      >>> get_max_value([10, 10, 10])
      10
      """
      return max(numbers)
output:     if not numbers:
          return None