fix cwe prefix

lm_eval/tasks/ruler/cwe.yaml

 include: niah_single_1.yaml
 task: ruler_cwe
 download_dataset: !function cwe_utils.get_cw_dataset
+target_delimiter: "\n\n"
 generation_kwargs:
   do_sample: false
   temperature: 0.0

lm_eval/tasks/ruler/cwe_utils.py

@@ -22,7 +22,7 @@ from lm_eval.tasks.ruler.common_utils import DEFAULT_SEQ_LENGTHS, get_tokenizer
 
 
 RNG = random.Random(42)
-TEMPLATE = "Below is a numbered list of words. In these words, some appear more often than others. Memorize the ones that appear most often.\n{context}\nQuestion: What are the 10 most common words in the above list?\n\nAnswer: The top 10 words that appear most often in the list are:"
+TEMPLATE = "Below is a numbered list of words. In these words, some appear more often than others. Memorize the ones that appear most often.\n{context}\nQuestion: What are the 10 most common words in the above list?"
 
 
 r = wonderwords.RandomWord()

lm_eval/utils.py

@@ -114,6 +114,8 @@ def simple_parse_args_string(args_string: Optional[str]) -> dict:
 
 def parse_keyed_list_string(s: str) -> dict[str, list]:
     """Parse a string of key-value pairs into a dictionary where all values are lists."""
+    if s is None:
+        return {}
     result = {}
     current_key = None
     values = []