Add test to showcase sequence issues when adding moves

NEWS.rst

@@ -7,6 +7,8 @@
 
 Modernize tests.
 
+Fix sequence issues when creating alternate moves.
+
 16.0.1.0.0
 ==========
 

tests/test_alternate_ledger.py

@@ -61,6 +61,10 @@
         )
         self.assertEqual(self._count_moves(), 1)
 
+    def test_copy(self):
+        self.move.copy()
+        self.assertEqual(self._count_moves(), 2)
+
     def test_delete(self):
         self.assertTrue(self.move.unlink())
         self.assertEqual(self._count_moves(), 0)