Add test_get_missing_records test

tests/test_lottery_predictor_collect.py

@@ -16,3 +16,10 @@ def test_get_recent_draw_date() -> None:
     assert isinstance(collect.get_recent_draw_date(table_name='MegaMillionsDraw'), datetime.date)
     with pytest.raises(ValueError):
         collect.get_recent_draw_date(table_name='SomeNonExistentTable')
+
+
+def test_get_missing_records() -> None:
+    assert isinstance(collect.get_missing_records(table_name='PowerballDraw'), int)
+    assert isinstance(collect.get_missing_records(table_name='MegaMillionsDraw'), int)
+    with pytest.raises(ValueError):
+        collect.get_missing_records(table_name='SomeNonExistentTable')