text: # basic test
  s = {1}
  print(s.remove(1))
  print(list(s))
  try:
      print(s.remove(1), "!!!")
  except KeyError:
      pass
  else:
      print("failed to raise KeyError")
  
  # test sets of varying size
  for n in range(20):
      print('testing set with {} items'.format(n))
      for i in range(n):
          # create set
          s = set()
          for j in range(n):
              s.add(str(j))
          print(len(s))
  
          # delete an item
          s.remove(str(i))
          print(len(s))
  
          # check items
          for j in range(n):
              if str(j) in s:
                  if j == i:
                      print(j, 'in s, but it should not be')
              else:
                  if j != i:
                      print(j, 'not in s, but it should be')
  