def set_object_metadata(self, container, obj, metadata, clear=False,
            extra_info=None, prefix=None):
        """
        Accepts a dictionary of metadata key/value pairs and updates the
        specified object metadata with them.

        If 'clear' is True, any existing metadata is deleted and only the
        passed metadata is retained. Otherwise, the values passed here update
        the object's metadata.

        'extra_info; is an optional dictionary which will be populated with
        'status', 'reason', and 'headers' keys from the underlying swiftclient
        call.

        By default, the standard object metadata prefix ('X-Object-Meta-') is
        prepended to the header name if it isn't present. For non-standard
        headers, you must include a non-None prefix, such as an empty string.
        """
        return container.set_object_metadata(obj, metadata, clear=clear,
                prefix=prefix)
Accepts a dictionary of metadata key/value pairs and updates the
        specified object metadata with them.

        If 'clear' is True, any existing metadata is deleted and only the
        passed metadata is retained. Otherwise, the values passed here update
        the object's metadata.

        'extra_info; is an optional dictionary which will be populated with
        'status', 'reason', and 'headers' keys from the underlying swiftclient
        call.

        By default, the standard object metadata prefix ('X-Object-Meta-') is
        prepended to the header name if it isn't present. For non-standard
        headers, you must include a non-None prefix, such as an empty string.