old_contents: N = 1000
  for n in range(2, N+1):
      for a in range(2, n):
          if n % a == 0:
              break
          else:
              print(n)
  
new_contents: N = 1000
  for n in range(2, N+1):
      for a in range(2, n):
          if n % a == 0:
              break
      else:
          print(n)
  
subject: Create Individual class #2 truly