def METHOD_NAME(self, key, value, user_id=None, default=None, description=None, config=None):
    '''Create config entry.
    Args:
        key (str): Config key
        value (obj): Value for the config entry
        user_id (None or int): Id of user who created this entry
        default (None or obj): Default value for this config entry
        description (None or str): Description for this config entry
    Note:
        Will throw exception if key is already present in config!
    '''
    entry = self.dbm.get_project_config(key)
    if entry is None:
        if default is None:
            default = value
        entry = model.Config(key=key, default_value=try_dump(default), value=try_dump(value),
                             user_id=user_id, timestamp=int(time.time()), description=description, config=config
                             )
        self.dbm.save_obj(entry)
    else:
        raise Exception(
            'Config entry already exists! Can not create key: {}!'.format(key))