class_docstr: Remove html blocks from the text and store them for later retrieval.
code: def run(self, lines: list[str]) -> list[str]:
      source = "\n".join(lines)
      parser = HTMLExtractorExtra(self.md)
      parser.feed(source)
      parser.close()
      return "".join(parser.cleandoc).split("\n")
  
imports: from __future__ import annotations
  from .None import Extension
  from ..blockprocessors import BlockProcessor
  from ..preprocessors import Preprocessor
  from ..postprocessors import RawHtmlPostprocessor
  from ..None import util
  from ..htmlparser import HTMLExtractor, blank_line_re
  import xml.etree.ElementTree
  from typing import TYPE_CHECKING, Literal, Mapping
label_desc: Use image node_id 1 for calling the HtmlBlockPreprocessor obj's underlying member method code with example usage: obj.run(lines) and returns: str