code: def get_impact_report_as_string(analysis_dir):
      
      html_report_products = [
          'impact-report-output.html',
          'multi-exposure-impact-report-output.html']
      output_dir_path = join(analysis_dir, 'output')
  
      for html_report_product in html_report_products:
          table_report_path = join(output_dir_path, html_report_product)
          if exists(table_report_path):
              break
          table_report_path = None
  
      if not table_report_path:
          return None
  
      # We can display an impact report.
      # We need to open the file in UTF-8, the HTML may have some accents
      with open(table_report_path, 'r', encoding='utf-8') as table_report_file:
          report = table_report_file.read()
          return report
docs: Retrieve an html string of table report (impact-report-output.html).
  
      :param analysis_dir: Directory of where the report located.
      :type analysis_dir: str
  
      :return: HTML string of the report.
      :rtype: str