code: def exists(*paths):
      
      for path in paths:
          log(_("checking that {} exists...").format(path))
          if not os.path.exists(path):
              raise Failure(_("{} not found").format(path))
docs: Assert that all given paths exist.
  
      :params paths: files/directories to be checked for existence
      :raises check50.Failure: if any ``path in paths`` does not exist
  
      Example usage::
  
          check50.exists("foo.c", "foo.h")