Update dec2024.md

docs/release_notes/2024/dec2024.md

@@ -11,7 +11,7 @@ tags:
 
 ## 3.4.2.\* (December 13, 2024)
 
-- Prophecy Python libs version: 1.9.24
+- Prophecy Python libs version: 1.9.27
 - Prophecy Scala libs version: 8.6.0
 
 ### Features {#Features342}
@@ -42,7 +42,12 @@ For more information on the APIs, see Active and Total Users.
 
 - **"Offset" column name bug fix**: We fixed a bug where naming a column using a Snowflake reserved keyword, such as "Offset", would break when using a Reformat Gem.
 
-- **New Spark Fabric diagnotic error codes**: There are new diagnostic error codes for the following failures:
+- **Support for null values in unit tests**: We added support for null values in unit tests. Once you upgrade your Prophecy Scala libs to 8.6.0 or later and your Prophecy Python libs to 1.9.27 or later, you should see an uncommitted diff in `prophecy/tests/*.json`. The null values will be changed to "". This won't affect anything in actual code of your Pipeline, and existing unit tests should continue working as is.
+
+- **New Spark Fabric diagnostic error codes**: There are new diagnostic error codes for the following failures:
+
   - Unable to reach Databricks endpoint.
   - Unable to write execution metrics because Hive Metastore is not enabled on your Spark.
   - Authentication fails while attempting to test a Spark Fabric connection.
+
+  For more information, see [Diagnostics](../../Spark/fabrics/diagnostics.md).