Adding documentation

Author: leandrodamascena

docs/core/logger.md

@@ -274,6 +274,16 @@ Logger is commonly initialized in the global scope. Due to [Lambda Execution Con
     --8<-- "examples/logger/src/clear_state_event_two.json"
     ```
 
+### Accessing currently configured keys
+
+You can view all currently configured keys from the Logger state using the `get_current_keys()` method. This method is useful when you need to avoid overwriting keys that are already configured.
+
+=== "get_current_keys.py"
+
+    ```python hl_lines="4 11"
+    --8<-- "examples/logger/src/get_current_keys.py"
+    ```
+
 ### Log levels
 
 The default log level is `INFO`. It can be set using the `level` constructor option, `setLevel()` method or by using the `POWERTOOLS_LOG_LEVEL` environment variable.

examples/logger/src/get_current_keys.py

@@ -0,0 +1,14 @@
+from aws_lambda_powertools import Logger
+from aws_lambda_powertools.utilities.typing import LambdaContext
+
+logger = Logger()
+
+
+@logger.inject_lambda_context
+def lambda_handler(event: dict, context: LambdaContext) -> str:
+    logger.info("Collecting payment")
+
+    if "order" not in logger.get_current_keys():
+        logger.append_keys(order=event.get("order"))
+
+    return "hello world"

tests/functional/test_logger.py

@@ -614,11 +614,12 @@ def test_logger_append_and_show_current_keys(stdout, service_name):
     logger.append_keys(**extra_keys)
 
     # THEN appended keys must be present in logger
-    assert "request_id" in logger.get_current_keys()
-    assert "context" in logger.get_current_keys()
+    current_keys = logger.get_current_keys()
+    assert "request_id" in current_keys
+    assert "context" in current_keys
 
 
-def test_logger_formatter_without_current_keys_method(stdout, service_name):
+def test_logger_formatter_without_get_current_keys_method(stdout, service_name):
     class CustomFormatter(BasePowertoolsFormatter):
         def append_keys(self, **additional_keys):
             # Fake method