Set default options for a session.

        Set default options for a session. whether in a Python script or
        a Jupyter notebook.

        Args:
           *options: Option objects used to specify the defaults.
           backend:  The plotting extension the options apply to

def defaults(cls, *options, **kwargs):
        """Set default options for a session.

        Set default options for a session. whether in a Python script or
        a Jupyter notebook.

        Args:
           *options: Option objects used to specify the defaults.
           backend:  The plotting extension the options apply to
        """
        if kwargs and len(kwargs) != 1 and list(kwargs.keys())[0] != 'backend':
            raise Exception('opts.defaults only accepts "backend" keyword argument')

        cls._linemagic(cls._expand_options(merge_options_to_dict(options)), backend=kwargs.get('backend'))