code: def limit_text_to_be_path_element(text, max_length=None, separator='_'):
      
      # TODO: Should there not only be one method i.e. either this one or "clean_path_element"
      elements_to_replace = {' ': '_', '*': '_'}
      for elem, replace_with in elements_to_replace.items():
          text = text.replace(elem, replace_with)
      text = re.sub('[^a-zA-Z0-9-_]', '', text)
      if max_length is not None:
          text = limit_text_max_length(text, max_length, separator)
      return text
docs: Replace characters that are not in the valid character set of RAFCON.
  
      :param text: the string to be cleaned
      :param max_length: the maximum length of the output string
      :param separator: the separator used for rafcon.core.storage.storage.limit_text_max_length
      :return: