edge case when in getLineContentScore both args are [], sacrebleu doesn't work properly

logmetric.py

@@ -147,7 +147,9 @@ class LogMetric(evaluate.Metric):
     
     # Get differenct scores regarding the content of a log-message
     def getLineContentScore(self, pred_logMessages, ref_logMessages):
-        sacrebleu_score = self.sacrebleu_metric.compute(predictions=pred_logMessages, references=ref_logMessages)["score"]/ 100.0
+        if pred_logMessages == [] and ref_logMessages == []:
+            pred_logMessages, ref_logMessages = [""]
+        sacrebleu_score = self.sacrebleu_metric.compute(predictions=pred_logMessages, references=ref_logMessages)["score"] / 100.0
         
         smape_length_score = self.get_length_score(pred_logMessages, ref_logMessages)