code: def endofcell_marker(source, comment):
      """Issues #31 #38:  does the cell contain a blank line? In that case
      we add an end-of-cell marker"""
      endofcell = "-"
      while True:
          endofcell_re = re.compile(
              rf"^{re.escape(comment)}( )" + endofcell + r"\s*$"
          )
          if list(filter(endofcell_re.match, source)):
              endofcell = endofcell + "-"
          else:
              return endofcell
  
imports: import re
  import warnings
  from copy import copy
  from .cell_metadata import _IGNORE_CELL_METADATA, is_active, metadata_to_double_percent_options, metadata_to_rmd_options, metadata_to_text
  from .cell_reader import LightScriptCellReader, MarkdownCellReader, RMarkdownCellReader
  from .doxygen import markdown_to_doxygen
  from .languages import _SCRIPT_EXTENSIONS, cell_language, comment_lines, same_language
  from .magics import comment_magic, escape_code_start, need_explicit_marker
  from .metadata_filter import filter_metadata
  from .pep8 import pep8_lines_between_cells
label_desc: Use image node_id 3 for calling a global function with example usage: endofcell_marker(source, comment) and returns: endofcell