feat(community): make Amadeus toolkit LLM-agnostic (#15879)

- **Description:** `AmadeusToolkit` and `AmadeusClosestAirport`
contained a hardcoded call to `ChatOpenAI`. This PR makes it
LLM-independent, while guaranteeing backward compatibility.
  - **Issue:** #15847 
  - **Dependencies:** None
   
@baskaryan 

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libs/community/langchain_community/agent_toolkits/amadeus/toolkit.py

@@ -1,7 +1,8 @@
 from __future__ import annotations
 
-from typing import TYPE_CHECKING, List
+from typing import TYPE_CHECKING, List, Optional
 
+from langchain_core.language_models import BaseLanguageModel
 from langchain_core.pydantic_v1 import Field
 
 from langchain_community.agent_toolkits.base import BaseToolkit
@@ -18,6 +19,7 @@ class AmadeusToolkit(BaseToolkit):
     """Toolkit for interacting with Amadeus which offers APIs for travel."""
 
     client: Client = Field(default_factory=authenticate)
+    llm: Optional[BaseLanguageModel] = Field(default=None)
 
     class Config:
         """Pydantic config."""
@@ -27,6 +29,6 @@ class AmadeusToolkit(BaseToolkit):
     def get_tools(self) -> List[BaseTool]:
         """Get the tools in the toolkit."""
         return [
-            AmadeusClosestAirport(),
+            AmadeusClosestAirport(llm=self.llm),
             AmadeusFlightSearch(),
         ]

libs/community/langchain_community/tools/amadeus/closest_airport.py

@@ -1,7 +1,8 @@
-from typing import Optional, Type
+from typing import Any, Dict, Optional, Type
 
 from langchain_core.callbacks import CallbackManagerForToolRun
-from langchain_core.pydantic_v1 import BaseModel, Field
+from langchain_core.language_models import BaseLanguageModel
+from langchain_core.pydantic_v1 import BaseModel, Field, root_validator
 
 from langchain_community.chat_models import ChatOpenAI
 from langchain_community.tools.amadeus.base import AmadeusBaseTool
@@ -35,6 +36,16 @@ class AmadeusClosestAirport(AmadeusBaseTool):
     )
     args_schema: Type[ClosestAirportSchema] = ClosestAirportSchema
 
+    llm: Optional[BaseLanguageModel] = Field(default=None)
+    """Tool's llm used for calculating the closest airport. Defaults to `ChatOpenAI`."""
+
+    @root_validator(pre=True)
+    def set_llm(cls, values: Dict[str, Any]) -> Dict[str, Any]:
+        if not values.get("llm"):
+            # For backward-compatibility
+            values["llm"] = ChatOpenAI(temperature=0)
+        return values
+
     def _run(
         self,
         location: str,
@@ -47,4 +58,4 @@ class AmadeusClosestAirport(AmadeusBaseTool):
             ' Location Identifier" '
         )
 
-        return ChatOpenAI(temperature=0).predict(content)
+        return self.llm.predict(content)