input: Write a function to print the absolute difference between two given numbers. The function should take two parameters and return the absolute difference. If the given numbers are empty then return 0.
  
  def absolute_difference(A, B):
      if A is None or B is None:
          return 0
      return abs(A - B)
  
  assert absolute_difference(9, 5) == 4
  assert absolute_difference(3, 11) == 8
  assert absolute_difference(-3, 7) == 10
  assert absolute_difference(0, 0) == 0
  assert absolute_difference(None, 5) == 0
  assert absolute_difference(3, None) == 0
output: def absolute_difference(A, B):
      if A is None or B is None:
          return 0
      return abs(A - B)