class_docstr: Unit tests for Agent class
code: def test_clarification_questions(self, sample_df, config):
      agent = Agent(sample_df, config, memory_size=10)
      agent._lake.llm.call = Mock()
      clarification_response = '["What is happiest index for you?", "What is unit of measure for gdp?"]'
      agent._lake.llm.call.return_value = clarification_response
  
      questions = agent.clarification_questions(
          "What is the happiest country?"
      )
      assert len(questions) == 2
      assert questions[0] == "What is happiest index for you?"
      assert questions[1] == "What is unit of measure for gdp?"
  
imports: from typing import Optional
  from unittest.mock import Mock
  from pandasai.agent import Agent
  import pandas
  import pytest
  from pandasai.llm.fake import FakeLLM
  from pandasai.prompts.clarification_questions_prompt import ClarificationQuestionPrompt
  from pandasai.prompts.explain_prompt import ExplainPrompt
  from pandasai.smart_datalake import SmartDatalake
label_desc: Use image node_id 8 for calling the TestAgent obj's underlying member method code with example usage: obj.test_clarification_questions(sample_df, config) without return types