code: def comment_magic(source, language='python', global_escape_flag=True):
      
      parser = StringParser(language)
      next_is_magic = False
      for pos, line in enumerate(source):
          if not parser.is_quoted() and (next_is_magic or is_magic(line, language, global_escape_flag)):
              source[pos] = _COMMENT[language] + ' ' + line
              next_is_magic = language == 'python' and _LINE_CONTINUATION_RE.match(line)
          parser.read_line(line)
      return source
docs: Escape Jupyter magics with '#