chore: import upstream snapshot with attribution

examples/flows/evaluation/eval-summarization-maf/aggregation.py

@@ -0,0 +1,19 @@
+from typing import Dict, List
+
+
+def aggregate(
+    coherence: List[float],
+    consistency: List[float],
+    fluency: List[float],
+    relevance: List[float],
+) -> Dict[str, float]:
+    average_fluency = sum(fluency) / len(fluency) if fluency else 0.0
+    average_consistency = sum(consistency) / len(consistency) if consistency else 0.0
+    average_relevance = sum(relevance) / len(relevance) if relevance else 0.0
+    average_coherence = sum(coherence) / len(coherence) if coherence else 0.0
+    return {
+        "average_fluency": average_fluency,
+        "average_consistency": average_consistency,
+        "average_relevance": average_relevance,
+        "average_coherence": average_coherence,
+    }