class_docstr: Base class for prompts supposed to read template content from a file.
  
  `_path_to_template` attribute has to be specified.
code: def template(self) -> str:
      try:
          with open(self._path_to_template, encoding="utf-8") as fp:
              return fp.read()
      except FileNotFoundError as e:
          raise TemplateFileNotFoundError(
              self._path_to_template, self.__class__.__name__
          ) from e
      except IOError as exc:
          raise RuntimeError(
              f"Failed to read template file '{self._path_to_template}': {exc}"
          ) from exc
  
file_path: pandas-ai/pandasai/prompts/file_based_prompt.py
imports: import os
  from pathlib import Path
  from ..exceptions import TemplateFileNotFoundError
  from .base import AbstractPrompt
label_desc: Use image node_id 2 for calling the FileBasedPrompt obj's underlying member method code with example usage: obj.template() and returns: fp