How to use the notebook.config_manager.BaseJSONConfigManager function in notebook

def test_nbextensionpy_enable(self):
        self._inject_mock_extension('notebook')
        install_nbextension_python('mockextension', user=True)
        enable_nbextension_python('mockextension')
        
        config_dir = os.path.join(_get_config_dir(user=True), 'nbconfig')
        cm = BaseJSONConfigManager(config_dir=config_dir)
        enabled = cm.get('notebook').get('load_extensions', {}).get('_mockdestination/index', False)
        assert enabled

def _get_config(self, user=True):
        cm = BaseJSONConfigManager(config_dir=_get_config_dir(user))
        data = cm.get("jupyter_notebook_config")
        return data.get("NotebookApp", {}).get("nbserver_extensions", {})

def test_nbextension_disable(self):
        self.test_nbextension_enable()
        disable_nbextension(section='notebook', require=u'ƒ')
        
        config_dir = os.path.join(_get_config_dir(user=True), 'nbconfig')
        cm = BaseJSONConfigManager(config_dir=config_dir)
        enabled = cm.get('notebook').get('load_extensions', {}).get(u'ƒ', False)
        assert not enabled

"""
    nbext = _get_nbextension_dir(user=user, sys_prefix=sys_prefix, prefix=prefix, nbextensions_dir=nbextensions_dir)
    dest = cast_unicode_py2(dest)
    full_dest = pjoin(nbext, dest)
    if os.path.lexists(full_dest):
        if logger:
            logger.info("Removing: %s" % full_dest)
        if os.path.isdir(full_dest) and not os.path.islink(full_dest):
            shutil.rmtree(full_dest)
        else:
            os.remove(full_dest)
    
    # Look through all of the config sections making sure that the nbextension
    # doesn't exist.
    config_dir = os.path.join(_get_config_dir(user=user, sys_prefix=sys_prefix), 'nbconfig')
    cm = BaseJSONConfigManager(config_dir=config_dir)
    if require:
        for section in NBCONFIG_SECTIONS:
            cm.update(section, {"load_extensions": {require: None}})

require : string
        An importable AMD module inside the nbextensions static path
    state : bool
        The state in which to leave the extension
    user : bool [default: True]
        Whether to update the user's .jupyter/nbextensions directory
    sys_prefix : bool [default: False]
        Whether to update the sys.prefix, i.e. environment. Will override
        `user`.
    logger : Jupyter logger [optional]
        Logger instance to use
    """
    user = False if sys_prefix else user
    config_dir = os.path.join(
        _get_config_dir(user=user, sys_prefix=sys_prefix), 'nbconfig')
    cm = BaseJSONConfigManager(config_dir=config_dir)
    if logger:
        logger.info("{} {} extension {}...".format(
            "Enabling" if state else "Disabling",
            section,
            require
        ))
    cm.update(section, {"load_extensions": {require: state}})

    validate_nbextension(require, logger=logger)

    return cm.get(section).get(require) == state

`load_jupyter_server_extension` function
    enabled : bool [default: None]
        Toggle state for the extension.  Set to None to toggle, True to enable,
        and False to disable the extension.
    parent : Configurable [default: None]
    user : bool [default: True]
        Toggle in the user's configuration location (e.g. ~/.jupyter).
    sys_prefix : bool [default: False]
        Toggle in the current Python environment's configuration location
        (e.g. ~/.envs/my-env/etc/jupyter). Will override `user`.
    logger : Jupyter logger [optional]
        Logger instance to use
    """
    user = False if sys_prefix else user
    config_dir = _get_config_dir(user=user, sys_prefix=sys_prefix)
    cm = BaseJSONConfigManager(parent=parent, config_dir=config_dir)
    cfg = cm.get("jupyter_notebook_config")
    server_extensions = (
        cfg.setdefault("NotebookApp", {})
        .setdefault("nbserver_extensions", {})
    )

    old_enabled = server_extensions.get(import_name, None)
    new_enabled = enabled if enabled is not None else not old_enabled

    if logger:
        if new_enabled:
            logger.info(u"Enabling: %s" % (import_name))
        else:
            logger.info(u"Disabling: %s" % (import_name))

    server_extensions[import_name] = new_enabled

def list_nbextensions(self):
        """List all the nbextensions"""
        config_dirs = [os.path.join(p, 'nbconfig') for p in jupyter_config_path()]
        
        print("Known nbextensions:")
        
        for config_dir in config_dirs:
            head = u'  config dir: {}'.format(config_dir)
            head_shown = False

            cm = BaseJSONConfigManager(parent=self, config_dir=config_dir)
            for section in NBCONFIG_SECTIONS:
                data = cm.get(section)
                if 'load_extensions' in data:
                    if not head_shown:
                        # only show heading if there is an nbextension here
                        print(head)
                        head_shown = True
                    print(u'    {} section'.format(section))
                    
                    for require, enabled in data['load_extensions'].items():
                        print(u'      {} {}'.format(
                            require,
                            GREEN_ENABLED if enabled else RED_DISABLED))
                        if enabled:
                            validate_nbextension(require, logger=self.log)