Fix: Add Returns Section and Usage Example to LLMMathChain.from_llm Docstring

Step-by-Step Solution Plan

1. Update LLMMathChain.from_llm Docstring

• Add a Returns section to describe the return type and value of the method.
• Add a usage example to demonstrate how to use the method.

2. Example Code

class LLMMathChain:
    # ... existing code ...

    def from_llm(self, llm_model: str) -> 'LLMMathChain':
        """
        Initialize the math chain from a given LLM model.

        Args:
            llm_model (str): The name of the LLM model to use.

        Returns:
            LLMMathChain: The initialized math chain.

        Example:
            >>> math_chain = LLMMathChain.from_llm('my_llm_model')
            >>> math_chain.perform_math_operation()
        """
        # ... existing code ...

3. Commit Message

• "Added Returns section and usage example to LLMMathChain.from_llm docstring"

4. Verification

• Run python -m pydoc -w LLMMathChain to generate HTML documentation for the class.
• Verify that the Returns section and usage example are present in the generated documentation.