input: Write a function to return the largest value from a given list of numbers.
  
  def get_max_value(numbers):
      return max(numbers)
  
  assert get_max_value([2, 4, 1, 6]) == 6
  assert get_max_value([10, 5, 8, 3]) == 10
  assert get_max_value([7, 7, 7, 7]) == 7
  assert get_max_value([-1, -5, -3, -2]) == -1
  assert get_max_value([]) == None
output: def get_max_value(numbers):
      if not numbers:
          return None
      return max(numbers)