@classmethod
def dump(cls, level, action, **kwargs):
    """A method for sub-class to override.

        :param level: An integer as defined by python logging module.
        :param action: The action that triggered this dump.
        :param dict kwargs: Additional parameters such as ``phase``,
                            ``timestamp`` or ``extra``.
        :returns: None
        """
    raise NotImplementedError
