code: def _render_headers(self):
          
          headers = getattr(self, 'headers', ())
          for index, col in enumerate(headers):
              # We write the headers
              cell = self.worksheet.cell(row=1, column=index + 1)
              cell.value = col['label']
  
          index += 1
  
          extra_headers = getattr(self, 'extra_headers', ())
          for add_index, col in enumerate(extra_headers):
              cell = self.worksheet.cell(row=1, column=add_index + index + 1)
              cell.value = col['label']
docs: Write the headers row