def METHOD_NAME(self):
    """
    Test that default discussion_id values are not exported.
    Historically, the OLX format allowed omitting discussion ID values; in such case, the IDs are generated
    deterministically based on the course ID and the usage ID. Moreover, Studio does not allow course authors
    to edit discussion_id, so all courses authored in Studio have discussion_id omitted in OLX.
    Forcing Studio to always export discussion_id can cause data loss when switching between an older and newer
    export,  in a course with a course ID different from the one from which the export was created - because the
    discussion ID would be different.
    """
    target_node = etree.Element('dummy')
    block = DiscussionXBlock(self.runtime_mock, scope_ids=self.keys, field_data=DictFieldData({}))
    discussion_id_field = block.fields['discussion_id']  # pylint: disable=unsubscriptable-object
    # precondition checks - discussion_id does not have a value and uses UNIQUE_ID
    assert discussion_id_field._get_cached_value(block) == NO_CACHE_VALUE  # pylint: disable=W0212
    assert discussion_id_field.default == UNIQUE_ID
    block.add_xml_to_node(target_node)
    assert target_node.tag == 'discussion'  # pylint: disable=W0212
    assert 'discussion_id' not in target_node.attrib