Amadeus toolkit minor update (#13002)

- update `Amadeus` toolkit with ability to switch Amadeus environments 
- update minor code explanations

---------

Co-authored-by: MinjiK <minji.kim@amadeus.com>

libs/langchain/langchain/agents/agent_toolkits/amadeus/toolkit.py

@@ -15,7 +15,7 @@ if TYPE_CHECKING:
 
 
 class AmadeusToolkit(BaseToolkit):
-    """Toolkit for interacting with Amadeus which offers APIs for travel search."""
+    """Toolkit for interacting with Amadeus which offers APIs for travel."""
 
     client: Client = Field(default_factory=authenticate)
 

libs/langchain/langchain/tools/amadeus/flight_search.py

@@ -96,7 +96,7 @@ class AmadeusFlightSearch(AmadeusBaseTool):
             )
             return [None]
 
-        # Collect all results from the API
+        # Collect all results from the Amadeus Flight Offers Search API
         try:
             response = client.shopping.flight_offers_search.get(
                 originLocationCode=originLocationCode,

libs/langchain/langchain/tools/amadeus/utils.py

@@ -33,6 +33,10 @@ def authenticate() -> Client:
         )
         return None
 
-    client = Client(client_id=client_id, client_secret=client_secret)
+    hostname = "test"  # Default hostname
+    if "AMADEUS_HOSTNAME" in os.environ:
+        hostname = os.environ["AMADEUS_HOSTNAME"]
+
+    client = Client(client_id=client_id, client_secret=client_secret, hostname=hostname)
 
     return client