Added get_image test of stitched sample

tests/test_parser.py

@@ -4,6 +4,7 @@ from nd2reader.artificial import ArtificialND2
 from nd2reader.common import check_or_make_dir
 from nd2reader.exceptions import InvalidVersionError
 from nd2reader.parser import Parser
+import urllib.request
 
 
 class TestParser(unittest.TestCase):
@@ -13,15 +14,24 @@ class TestParser(unittest.TestCase):
 
     def setUp(self):
         dir_path = path.dirname(path.realpath(__file__))
-        check_or_make_dir(path.join(dir_path, 'test_data/'))
-        self.test_file = path.join(dir_path, 'test_data/test.nd2')
+        check_or_make_dir(path.join(dir_path, "test_data/"))
+        self.test_file = path.join(dir_path, "test_data/test.nd2")
         self.create_test_nd2()
 
     def test_can_open_test_file(self):
         self.create_test_nd2()
 
-        with open(self.test_file, 'rb') as fh:
+        with open(self.test_file, "rb") as fh:
             parser = Parser(fh)
             self.assertTrue(parser.supported)
 
-
+    def test_get_image(self):
+        stitched_path = "test_data/test_stitched.nd2"
+        if not path.isfile(stitched_path):
+            file_name, header = urllib.request.urlretrieve(
+                "https://downloads.openmicroscopy.org/images/ND2/karl/sample_image.nd2",
+                stitched_path,
+            )
+        with open(stitched_path, "rb") as fh:
+            parser = Parser(fh)
+            parser.get_image(0)