def METHOD_NAME(self,data_element, *keysarr) :
    '''
    Check if *keys (nested) exists in `element` (dict).
    '''
    if not isinstance(data_element, dict):
        raise AttributeError('keys_exists() expects dict as first argument.')
    if len(keysarr) == 0:
        raise AttributeError('keys_exists() expects at least two arguments, one given.')
    _element = data_element
    for key in list(keysarr):
        try:
            _element = _element[key]
        except KeyError:
            self.logger.debug('key not found: %s', key)
            return False
    return True