Fix NotImplementedError

✅ Solution

The "NotImplementedError" in Langchain usually arises when a base class or interface method is called without a concrete implementation in a subclass or a mock. To fix it, ensure the specific method throwing the error (e.g., `profile` access or structured output handling) is properly implemented in your custom class or ensure you are not using unsupported features with mock/fake objects. If using a base class, implement the missing method; if using a mock, avoid calling unimplemented functions.