def METHOD_NAME(relationship: GraphRelationship) -> str:
    return "{label}:{from_vertex_label}:{from_vertex_id}_{to_vertex_label}:{to_vertex_id}".format(
        from_vertex_id=relationship.start_key,
        from_vertex_label=relationship.start_label,
        to_vertex_id=relationship.end_key,
        to_vertex_label=relationship.end_label,
        label=relationship.type
    )