Improve code spacing

Signed-off-by: Loren Eteval <loren.eteval@proton.me>

tests/test_sing_tun_linux_host.py

@@ -103,6 +103,7 @@ class SingTUNLinuxHostTest(unittest.TestCase):
             Path(arguments[2]).parent.joinpath('ready').write_text(
                 '77', encoding='utf-8'
             )
+
             return process
 
         link = {'ifname': 'utun101', 'ifindex': 77}
@@ -117,8 +118,10 @@ class SingTUNLinuxHostTest(unittest.TestCase):
             self.module, '_command', return_value=json.dumps([link])
         ):
             self.host.prepare()
+
             with self.assertRaisesRegex(RuntimeError, 'already active'):
                 self.host.execute([])
+
             self.host.applyDNS('1.1.1.1')
 
         self.assertEqual(self.host.index, 77)
@@ -135,6 +138,7 @@ class SingTUNLinuxHostTest(unittest.TestCase):
         self.assertIn('/sys/class/net/utun101/ifindex', scripts[0])
         self.assertIn('resolvectl dns utun101 1.1.1.1', scripts[0])
         self.assertNotIn('socks5', ''.join(scripts))
+
         self.assertIs(self.host._process, process)
         self.assertIsNotNone(self.host._directory)
 
@@ -157,6 +161,7 @@ class SingTUNLinuxHostTest(unittest.TestCase):
                 checked = subprocess.run(
                     [bash, '-n', '-c', script], capture_output=True, timeout=5
                 )
+
                 self.assertEqual(
                     checked.returncode, 0, checked.stderr.decode(errors='replace')
                 )