<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def _parse_apps_to_sync(self):
 """ Parse the applications to backup in the config. Returns: set """

        # We allow nothing by default
        apps_to_sync = set()

        # Is the "[applications_to_sync]" section in the cfg file ?
        section_title = 'applications_to_sync'
        if self._parser.has_section(section_title):
            apps_to_sync = set(self._parser.options(section_title))

        return apps_to_sync