'Like set_attr but sets multiple key value pairs.
Returns nothing.
Raises NotFoundError if no such item exists
Raises AttributeError is attr_dict has any attrs which are one of the build in attrs.
:param location:  a c4x asset location'

def set_attrs(self, location, attr_dict):

    for attr in attr_dict.iterkeys():
        if (attr in ['_id', 'md5', 'uploadDate', 'length']):
            raise AttributeError('{}    is    a    protected    attribute.'.format(attr))
    (asset_db_key, __) = self.asset_db_key(location)
    result = self.fs_files.update({'_id': asset_db_key}, {'$set': attr_dict}, upsert=False)
    if (not result.get('updatedExisting', True)):
        raise NotFoundError(asset_db_key)
