code: def llm(self, output: Optional[str] = None):
      return FakeLLM(output=output)
  
imports: from typing import Optional
  from unittest.mock import MagicMock, Mock, patch
  import uuid
  import pandas
  import pytest
  from pandasai.agent import Agent
  from pandasai.helpers.code_manager import CodeExecutionContext, CodeManager
  from pandasai.helpers.skills_manager import SkillsManager
  from pandasai.llm.fake import FakeLLM
  from pandasai.skills import skill, Skill
  from pandasai.smart_dataframe import SmartDataframe
label_desc: Use image node_id 1 for calling the TestSkills obj's underlying member method code with example usage: obj.llm(output) and returns: FakeLLM