code: def _mac_ver():
      
      import platform
      import sys
      if sys.platform == 'darwin':
          ver_str = platform.mac_ver()[0]
          return tuple([int(v) for v in ver_str.split('.')])
      else:
          return ()
docs: Returns Mac version as a tuple of integers, making it easy to do proper
      version comparisons. On non-Macs, it returns an empty tuple.