diff --git a/trace_agg.py/tests/data/sample_trace.json b/trace_agg.py/tests/data/sample_trace.json
new file mode 100644
index 0000000..4b2e8e7
--- /dev/null
+++ b/trace_agg.py/tests/data/sample_trace.json
@@ -0,0 +1,47 @@
+[
+  {
+    "corr_id": 101,
+    "event_type": "write_pre",
+    "timestamp": 1.0001
+  },
+  {
+    "corr_id": 101,
+    "event_type": "read_between_steps",
+    "timestamp": 1.0005
+  },
+  {
+    "corr_id": 101,
+    "event_type": "write_post",
+    "timestamp": 1.0010
+  },
+  {
+    "corr_id": 102,
+    "event_type": "write_pre",
+    "timestamp": 2.1000
+  },
+  {
+    "corr_id": 102,
+    "event_type": "write_post",
+    "timestamp": 2.1030
+  },
+  {
+    "corr_id": 103,
+    "event_type": "write_pre",
+    "timestamp": 3.2000
+  },
+  {
+    "corr_id": 103,
+    "event_type": "read_between_steps",
+    "timestamp": 3.2010
+  },
+  {
+    "corr_id": 103,
+    "event_type": "read_between_steps",
+    "timestamp": 3.2020
+  },
+  {
+    "corr_id": 103,
+    "event_type": "write_post",
+    "timestamp": 3.2030
+  }
+]
\ No newline at end of file