https://github.com/RDFLib/OWL-RL/blob/a77e1791b88b54aace609bc6000aac14c7add4ff/scripts/owlrl#L90 `graph.serialize` could be [string](https://rdflib.readthedocs.io/en/stable/_modules/rdflib/graph.html#Graph.serialize) (which does not have .decode).
OWL-RL/scripts/owlrl
Line 90 in a77e179
graph.serializecould be string (which does not have .decode).