Pull-Request-Checklist.md

@@ -63,7 +63,28 @@ This section present some how-to to detect common problems
 
 ### Shippable: ensure up to date
 
-TODO: describe it.
+Shippable run this script: [`bin/utils/ensure-up-to-date`](https://github.com/OpenAPITools/openapi-generator/blob/master/bin/utils/ensure-up-to-date). In the logs it start with:
+
+```
+./bin/utils/ensure-up-to-date
+# START SCRIPT: ./bin/utils/ensure-up-to-date
+```
+
+On error case:
+
+```
+UNCOMMITTED CHANGES ERROR
+There are uncommitted changes in working tree after execution of 'bin/ensure-up-to-date'
+```
+
+Then you see the result of `git diff` (can be use full for debugging) and `git status`
+
+On error case, the scripts ends with:
+```
+Please run 'bin/utils/ensure-up-to-date' locally and commit changes (UNCOMMITTED CHANGES ERROR)
+```
+
+The PR needs to be updated so that the samples corresponds to the changes made to the generator.
 
 ### Shippable: generate all samples