setup fake test data

python/metrics/main.py

@@ -1,8 +1,24 @@
 import numpy as np
 import pandas as pd
 
+from time import perf_counter
+
 def main():
-    ...
+    rng = np.random.default_rng()
+    streamflow = pd.DataFrame(
+        {
+            "value_time": pd.date_range("2020-10-01", freq="1h", periods=100),
+            "value": rng.uniform(0.0, 1000.0, 100)
+        }
+    )
+    events = pd.DataFrame(
+        {
+            "start": np.random.choice(streamflow["value_time"], 10, replace=False)
+        }
+    )
+    events["end"] = events["start"].add(pd.Timedelta("1d"))
+
+    print(events.head())
 
 if __name__ == "__main__":
     main()