'Read the names of all the preconfigs from disk and store them in the
_preconfigs dictionary.'

def _init_preconfigs(self):

    if (not self._is_init):
        self._preconfigs['metrics'] = dict.fromkeys(os.listdir(self._get_preconfig_path(['metrics'])))
        self._preconfigs['qual'] = dict.fromkeys(os.listdir(self._get_preconfig_path(['qual'])))
        self._is_init = True
