Add test for headlines with no content lines.

tests/01-simple-2.org

@@ -0,0 +1,26 @@
+#+TITLE: 01-Simple-second
+#+DESCRIPTION: Simple org file
+#+TODO: TODO(t) PAUSED(p) |  DONE(d)
+
+
+* First level
+:PROPERTIES:
+:ID:       01-simple-first-level-id
+:CREATED:  [2020-01-01 Wed 01:01]
+:END:
+First level content
+
+** Second level
+   :PROPERTIES:
+   :ID:       01-simple-second-level-id
+   :END:
+
+   Second level content with no indentation
+
+*** Third level with no content
+**** Forth level
+    :PROPERTIES:
+    :ID:       01-simple-forth-level-id
+    :END:
+
+    Forth level content

tests/test_dom.py

@@ -40,7 +40,15 @@ class TestSerde(unittest.TestCase):
 
     def test_mimic_write_file_01(self):
         """A goal of this library is to be able to update a file without changing parts not directly modified."""
-        with open(os.path.join(DIR, '01-simple.org')) as f:
+        with open(os.path.join(DIR, "01-simple.org")) as f:
+            orig = f.read()
+            doc = loads(orig)
+
+        self.assertEqual(dumps(doc), orig)
+
+    def test_mimic_write_file_01_second(self):
+        """A goal of this library is to be able to update a file without changing parts not directly modified."""
+        with open(os.path.join(DIR, "01-simple-2.org")) as f:
             orig = f.read()
             doc = loads(orig)