code: def test_add_step(self, tracker: QueryExecTracker):
      # Create a sample step
      step = {
          "type": "CustomStep",
          "description": "This is a custom step.",
      }
  
      tracker._steps = []
      # Add the step to the tracker
      tracker.add_step(step)
  
      # Check if the step was added correctly
      assert len(tracker._steps) == 1
      assert tracker._steps[0] == step
  
imports: import json
  import os
  import time
  from typing import Optional
  from unittest.mock import MagicMock, Mock, patch
  import pandas
  import pytest
  from pandasai.helpers.query_exec_tracker import QueryExecTracker
  from pandasai.llm.fake import FakeLLM
  from pandasai.smart_dataframe import SmartDataframe
  from unittest import TestCase
  from datetime import datetime, timedelta
label_desc: Use image node_id 7 for calling the TestQueryExecTracker obj's underlying member method code with example usage: obj.test_add_step(tracker) without return types