def build_prompt(self, line: Union[int, pd.Series]) -> List[Dict[str, str]]:
        """
        Build a prompt for the model from a data line.

        Args:
            line: Either an index into the dataset or a pandas Series

        Returns:
            List of message dictionaries containing the image and question
        """
        if isinstance(line, int):
            line = self.data.iloc[line]

        if self.meta_only:
            tgt_path = misc.toliststr(line["image"])
        else:
            tgt_path = self.dump_image(line)

        messages = [{"type": "image", "value": tgt_path[0]}]
        messages.append({"type": "text", "value": line["question"]})
        return messages

        Build a prompt for the model from a data line.

        Args:
            line: Either an index into the dataset or a pandas Series

        Returns:
            List of message dictionaries containing the image and question
        
vlmeval/dataset/charxiv.py