docs: def _write_config(self, memory):
          """Write the configuration for this gate to memory."""
          memory.seek(0)
          memory.write(struct.pack("<5I",
                                   # sim_length
                                   self._simulator.length,
                                   # input_a_key
                                   self._inputs["a"].routing_key
                                   if self._inputs["a"] is not None
                                   else 0xFFFFFFFF,
                                   # input_b_key
                                   self._inputs["b"].routing_key
                                   if self._inputs["b"] is not None
                                   else 0xFFFFFFFF,
                                   # output_key
                                   self.output.routing_key,
                                   # lut
                                   self._lookup_table))