def METHOD_NAME(self, lti_params) -> Optional[Assignment]:
    """Return the assignment that the current assignment was copied from."""
    resource_link_history_params = [
        "resource_link_id_history",  # Blackboard, LTI 1.1
        "ext_d2l_resource_link_id_history",  # D2L, LTI 1.1
        "custom_ResourceLink.id.history",  # Blackboard and D2L, LTI 1.3
    ]
    for param in resource_link_history_params:
        if historical_resource_link_id := lti_params.get(param):
            # History might have a long chain of comma separated
            # copies of copies, take the most recent one.
            historical_resource_link_id = historical_resource_link_id.split(",")[0]
            if historical_assignment := self.get_assignment(
                tool_consumer_instance_guid=lti_params.get(
                    "tool_consumer_instance_guid"
                ),
                resource_link_id=historical_resource_link_id,
            ):
                return historical_assignment
    return None