code: def test_figure(self):
      report = BarChart(
          self.data,
          self.cols,
          model_name=self.model_name,
          dataset_name=self.dataset_name,
      )
  
      # Original unsorted data should cause an error
      self.assertRaises(ValueError, report.figure)
  
      # Sort should resolve that error
      report.sort()
      try:
          report.figure()
      except ValueError:
          self.fail("report.figure() raised ValueError unexpectedly!")
  
file_path: textflint/test/report/report_generator/test_report_generator.py
imports: import unittest
  import pandas
  from textflint.report.analyzer.analyzer import *
  from textflint.report.report_generator.report_generator import BarChart, ReportGenerator
label_desc: Use image node_id 7 for calling the TestBarChart obj's underlying member method code with example usage: obj.test_figure() without return types