old_contents: #!/bin/py 
  
  #from sys import platform 
  import os 
  
  def osCheck():
  	# Check if OS is UNIX-y 
  	if 'posix' not in os.name:		
              print("Non-POSIX system detected")
  
  osCheck()
  
new_contents: #!/bin/py 
  # check if POSIX
  
  import os 
  
  def osCheck():
      if 'posix' not in os.name:		
          print("Non-POSIX system detected")
  
  osCheck()
  
subject: fix spacing