def create_real_iso(self, output_dir):
""" Create a "real" ISO file, using make_iso() (ie genisoimage) """
# simple contents
compose_dir = output_dir.mkdir('my-test-contents')
f = compose_dir.join('contents.txt')
f.write('This text file will be on our ISO')
iso = Iso([])
argv = ['merfi', str(output_dir.join('my-test-contents'))]
iso.parse_args(argv)
iso.make_iso()
iso.make_sha256sum()
return iso
