class_docstr: Unit tests for Agent class
code: def test_call_prompt_success(self, agent: Agent):
      agent._lake.llm.call = Mock()
      clarification_response = """
  What is expected Salary Increase?
          """
      agent._lake.llm.call.return_value = clarification_response
      prompt = ExplainPrompt(
          conversation="test conversation",
          code="test code",
      )
      agent._call_llm_with_prompt(prompt)
      assert agent._lake.llm.call.call_count == 1
  
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 13 for calling the TestAgent obj's underlying member method code with example usage: obj.test_call_prompt_success(agent) without return types