SAR single node implementation header has pySpark implementation info 
SAR single node implementation header has pySpark implementation info instead of python implementation docstring.
diff --git a/reco_utils/recommender/sar/sar_singlenode.py b/reco_utils/recommender/sar/sar_singlenode.py
index 94ce927e..22d16601 100644
--- a/reco_utils/recommender/sar/sar_singlenode.py
+++ b/reco_utils/recommender/sar/sar_singlenode.py
@@ -1,13 +1,9 @@
 """
-Reference implementation of SAR in pySpark using Spark-SQL and some dataframe operations.
-This is supposed to be a super-performant implementation of SAR on Spark using pySpark.
+Reference implementation of SAR in python/numpy/pandas.
 
-PS: there is plenty of room for improvement, especially around the very last step of making a partial sort:
-1) Can be done using UDAFs
-2) UDAFs can be transformed into: pivot, series of UDF operations, pivot
-3) other DF operations.
+This is not meant to be particularly performant or scalable, just
+as a simple and readable implementation.
 """
-
 import numpy as np
 import pandas as pd
 import logging
['reco_utils/recommender/sar/sar_singlenode.py']