chore: lower cognitive overhead; add example docstring

Signed-off-by: heitorlessa <[email protected]>

Author: heitorlessa

aws_lambda_powertools/utilities/data_classes/kinesis_firehose_event.py

@@ -125,6 +125,41 @@ class KinesisFirehoseDataTransformationResponse:
     records : List[KinesisFirehoseResponseRecord]
         records of Kinesis Data Firehose response object,
         optional parameter at start. can be added later using `add_record` function.
+
+    Examples
+    --------
+
+    **Transforming data records**
+
+    ```python
+    from aws_lambda_powertools.utilities.data_classes import (
+        KinesisFirehoseDataTransformationRecord,
+        KinesisFirehoseDataTransformationResponse,
+        KinesisFirehoseEvent,
+    )
+    from aws_lambda_powertools.utilities.serialization import base64_from_json
+    from aws_lambda_powertools.utilities.typing import LambdaContext
+
+
+    def lambda_handler(event: dict, context: LambdaContext):
+        firehose_event = KinesisFirehoseEvent(event)
+        result = KinesisFirehoseDataTransformationResponse()
+
+        for record in firehose_event.records:
+            payload = record.data_as_text  # base64 decoded data as str
+
+            ## generate data to return
+            transformed_data = {"tool_used": "powertools_dataclass", "original_payload": payload}
+            processed_record = KinesisFirehoseDataTransformationRecord(
+                record_id=record.record_id,
+                data=base64_from_json(transformed_data),
+            )
+
+            result.add_record(processed_record)
+
+        # return transformed records
+        return result.asdict()
+    ```
     """
 
     records: List[KinesisFirehoseDataTransformationRecord] = field(default_factory=list)

examples/event_sources/src/kinesis_firehose_response.py

@@ -16,11 +16,11 @@ def lambda_handler(event: dict, context: LambdaContext):
 
         ## generate data to return
         transformed_data = {"tool_used": "powertools_dataclass", "original_payload": payload}
-
         processed_record = KinesisFirehoseDataTransformationRecord(
             record_id=record.record_id,
             data=base64_from_json(transformed_data),
         )
+
         result.add_record(processed_record)
 
     # return transformed records