'Deletes the block structure for the given root_block_usage_key
from the cache and storage.
Arguments:
root_block_usage_key (UsageKey) - The usage_key for the root
of the block structure that is to be removed.'

def delete(self, root_block_usage_key):

    bs_model = self._get_model(root_block_usage_key)
    self._cache.delete(self._encode_root_cache_key(bs_model))
    bs_model.delete()
    logger.info('BlockStructure:    Deleted    from    cache    and    store;    %s.', bs_model)
