'If the file exists, ``make_directory`` raises an OSError with EEXIST.
There is no particular reason for this exception rather than any
other.'

def test_make_directory_file_exists(self):

    path = self.make_temporary_file()
    error = self.assertRaises(OSError, make_directory, path)
    self.assertThat(error.errno, Equals(errno.EEXIST))
