code: def indented_tree_line_generator(el, max_lines=None):
      
      gen = tree_line_generator(el, max_lines)
      for start_ref, end_ref, indentation_level, line in gen:
          # Escape line
          if line.startswith('>'):
              line = '\\' + line
          yield start_ref, end_ref, '> '*indentation_level + line
docs: Like tree_line_generator, but yields tuples (start_ref, end_ref, line),
      where the line already takes the indentation into account by having "> "
      prepended. If a line already starts with ">", it is escaped ("\\>"). This
      makes it possible to reliably use methods that analyze plain text to detect
      quoting.