code: def __init__(self, *args, parser=None, **kwargs):
      from markdown_it import MarkdownIt
      from mdit_plain.renderer import RendererPlain
      from mdit_py_plugins.front_matter import front_matter_plugin
  
      self.parser = parser
      if self.parser is None:
          self.parser = MarkdownIt(
              "commonmark", renderer_cls=RendererPlain
          )
          self.parser.use(front_matter_plugin)
  
      kwargs.setdefault(
          "para_block_reader",
          partial(read_parse_blankline_block, parser=self.parser),
      )
      super().__init__(*args, **kwargs)
  
imports: from collections import namedtuple
  from functools import partial, wraps
  from nltk.corpus.reader.api import CategorizedCorpusReader
  from nltk.corpus.reader.plaintext import PlaintextCorpusReader
  from nltk.corpus.reader.util import concat, read_blankline_block
  from nltk.tokenize import blankline_tokenize, sent_tokenize, word_tokenize
label_desc: Use image node_id 1 to create a new MarkdownCorpusReader object from inherited base classes: PlaintextCorpusReader with example: obj = MarkdownCorpusReader()