def set_object_metadata(self, container, obj, metadata, clear=False,
            extra_info=None, prefix=None):
        return self._manager.set_object_metadata(container, obj, metadata,
                clear=clear, prefix=prefix)
Accepts a dictionary of metadata key/value pairs and updates the
dataset/ETHPy150Open rackspace/pyrax/pyrax/object_storage.py/StorageClient.set_object_metadata