Fix NotImplementedError

✅ Solution

The "NotImplementedError" in LangChain often arises when a class inherits from an abstract base class (like `StructuredTool`) and doesn't implement a required method (like `_run`). To fix this, either implement the missing synchronous `_run` method or, if only an asynchronous `_arun` method exists, provide a synchronous implementation that calls `asyncio.run(_arun(...))` or use `sync_to_async` if direct use of `asyncio.run` is not suitable for the execution environment.