Filter sensitive details like passwords from a configuration
        dictionary.

def _filter_config(self, config, fields=None):
        """
        Filter sensitive details like passwords from a configuration
        dictionary.
        """
        filter_fields_default = [
            'bind_password',
            'connection'
            ]

        filter_fields = fields or filter_fields_default
        return dict(
            map(
                lambda key: (key, '<hidden>' if key in filter_fields else config[key]),
                config.keys()
                )
            )