docs: def cell_to_text(self):
          """Return the text representation for the cell"""
          if self.cell_type == 'code':
              source = copy(self.source)
              return comment_magic(source, self.language, self.comment_magics)
  
          if 'cell_marker' in self.metadata:
              cell_marker = self.metadata.pop('cell_marker')
          else:
              cell_marker = self.default_cell_marker
  
          if self.source == ['']:
              return [cell_marker] if cell_marker in ['""', "''"] else ['""']
  
          if cell_marker in ['"""', "'''"]:
              return [cell_marker] + self.source + [cell_marker]
  
          return [cell_marker if cell_marker.startswith('#' * 20)
                  else self.default_cell_marker] + comment_lines(self.source, self.comment)