Fixing cache for multiple configurations

Author: leandrodamascena

aws_lambda_powertools/utilities/parameters/appconfig.py

@@ -99,7 +99,7 @@ def __init__(
         self.current_version = ""
 
         self._next_token: Dict[str, str] = {}  # nosec - token for get_latest_configuration executions
-        self.last_returned_value = ""
+        self.last_returned_value: Dict[str, str] = {}
 
     def _get(self, name: str, **sdk_options) -> str:
         """
@@ -126,10 +126,12 @@ def _get(self, name: str, **sdk_options) -> str:
         return_value = response["Configuration"].read()
         self._next_token[name] = response["NextPollConfigurationToken"]
 
+        # The return of get_latest_configuration can be null because this value is supposed to be cached
+        # on the customer side. We created a dict with the last returned value for the specific configuration
         if return_value:
-            self.last_returned_value = return_value
+            self.last_returned_value[name] = return_value
 
-        return self.last_returned_value
+        return self.last_returned_value[name]
 
     def _get_multiple(self, path: str, **sdk_options) -> Dict[str, str]:
         """