@classmethod
def process(cls, config_outliers, logger=None):
    """Parse the outliers field of the config dict.

        :param config_outliers: The configuration dict for the outliers field.
        :param logger:          A logger object for logging debug info. [default: None]

        :returns: an Outliers instance
        """
    import piff
    if 'type' not in config_outliers:
        raise ValueError("config['outliers'] has no type field")
    outliers_class = getattr(piff, config_outliers['type'] + 'Outliers')
    kwargs = outliers_class.parseKwargs(config_outliers, logger)
    outliers = outliers_class(**kwargs)
    return outliers
