def find_folder(self, parent_id):
    """
      find_folder(parent_id)
      :param str parent_id:  The parent folder to list.

      This method will return a list of sub-folders to a given parent folder.

      **Examples**::

        # Iterate through folders within the default 'calendar' folder.
        folders = service.folder().find_folder(parent_id='calendar')
        for folder in folders:
          print(folder.display_name)

        # Delete all folders within the 'calendar' folder.
        folders = service.folder().find_folder(parent_id='calendar')
        for folder in folders:
          folder.delete()
    """

    body = soap_request.find_folder(parent_id=parent_id, format=u'AllProperties')
    response_xml = self.service.send(body)
    return self._parse_response_for_find_folder(response_xml)