class_docstr: Read notebook cells from Markdown documents
class_docstr_tok: ["Read","notebook","cells","from","Markdown","documents"]
code: def options_to_metadata(self, options):
      if isinstance(options, tuple):
          self.end_code_re = re.compile("```" + options[0])
          options = " ".join(options[1:])
      else:
          self.end_code_re = re.compile(r"^```\s*$")
      self.cell_metadata_json = (
          self.cell_metadata_json or is_json_metadata(options)
      )
      return text_to_metadata(options)
  
imports: import re
  import warnings
  from copy import copy
  from nbformat.v4.nbbase import new_code_cell, new_markdown_cell, new_raw_cell
  from packaging.version import parse
  from .doxygen import doxygen_to_markdown
  from .languages import _SCRIPT_EXTENSIONS
  from .cell_metadata import is_active, is_json_metadata, rmd_options_to_metadata, text_to_metadata
  from .languages import _JUPYTER_LANGUAGES_LOWER_AND_UPPER
  from .magics import is_magic, need_explicit_marker, uncomment_magic, unescape_code_start
  from .pep8 import pep8_lines_between_cells
  from .stringparser import StringParser
label_desc: Use image node_id 3 for calling the MarkdownCellReader obj's underlying member method code with example usage: obj.options_to_metadata(options) and returns: text_to_metadata