diff --git a/latency_calculator/tests/data/test_mess_log.jsonl b/latency_calculator/tests/data/test_mess_log.jsonl
new file mode 100644
index 0000000..b7d0010
--- /dev/null
+++ b/latency_calculator/tests/data/test_mess_log.jsonl
@@ -0,0 +1,22 @@
+[
+{"t_publish": "2024-05-01T10:00:00Z", "t_gate_read": "2024-05-01T10:00:02Z", "t_index_visible": "2024-05-01T10:00:03Z"},
+{"t_publish": "2024-05-01T10:01:00Z", "t_gate_read": "2024-05-01T10:01:02Z", "t_index_visible": "2024-05-01T10:01:04Z"},
+{"t_publish": "2024-05-01T10:02:00Z", "t_gate_read": "2024-05-01T10:02:03Z", "t_index_visible": "2024-05-01T10:02:05Z"},
+{"t_publish": "2024-05-01T10:03:00Z", "t_gate_read": "2024-05-01T10:03:02Z", "t_index_visible": "2024-05-01T10:03:05Z"},
+{"t_publish": "2024-05-01T10:04:00Z", "t_gate_read": "2024-05-01T10:04:01Z", "t_index_visible": "2024-05-01T10:04:03Z"},
+{"t_publish": "2024-05-01T10:05:00Z", "t_gate_read": "2024-05-01T10:05:02Z", "t_index_visible": "2024-05-01T10:05:06Z"},
+{"t_publish": "2024-05-01T10:06:00Z", "t_gate_read": "2024-05-01T10:06:03Z", "t_index_visible": "2024-05-01T10:06:05Z"},
+{"t_publish": "2024-05-01T10:07:00Z", "t_gate_read": "2024-05-01T10:07:02Z", "t_index_visible": "2024-05-01T10:07:04Z"},
+{"t_publish": "2024-05-01T10:08:00Z", "t_gate_read": "2024-05-01T10:08:02Z", "t_index_visible": "2024-05-01T10:08:05Z"},
+{"t_publish": "2024-05-01T10:09:00Z", "t_gate_read": "2024-05-01T10:09:03Z", "t_index_visible": "2024-05-01T10:09:04Z"},
+{"t_publish": "2024-05-01T10:10:00Z", "t_gate_read": "2024-05-01T10:10:02Z", "t_index_visible": "2024-05-01T10:10:06Z"},
+{"t_publish": "2024-05-01T10:11:00Z", "t_gate_read": "2024-05-01T10:11:03Z", "t_index_visible": "2024-05-01T10:11:07Z"},
+{"t_publish": "2024-05-01T10:12:00Z", "t_gate_read": "2024-05-01T10:12:01Z", "t_index_visible": "2024-05-01T10:12:04Z"},
+{"t_publish": "2024-05-01T10:13:00Z", "t_gate_read": "2024-05-01T10:13:03Z", "t_index_visible": "2024-05-01T10:13:05Z"},
+{"t_publish": "2024-05-01T10:14:00Z", "t_gate_read": "2024-05-01T10:14:02Z", "t_index_visible": "2024-05-01T10:14:06Z"},
+{"t_publish": "2024-05-01T10:15:00Z", "t_gate_read": "2024-05-01T10:15:04Z", "t_index_visible": "2024-05-01T10:15:08Z"},
+{"t_publish": "2024-05-01T10:16:00Z", "t_gate_read": "2024-05-01T10:16:01Z", "t_index_visible": "2024-05-01T10:16:02Z"},
+{"t_publish": "2024-05-01T10:17:00Z", "t_gate_read": "2024-05-01T10:17:02Z", "t_index_visible": "2024-05-01T10:17:04Z"},
+{"t_publish": "2024-05-01T10:18:00Z", "t_gate_read": "2024-05-01T10:18:03Z", "t_index_visible": "2024-05-01T10:18:06Z"},
+{"t_publish": "2024-05-01T10:19:00Z", "t_gate_read": "2024-05-01T10:19:02Z", "t_index_visible": "2024-05-01T10:19:03Z"}
+]
\ No newline at end of file