code: def goto_step(self, inst: InstanceNode) -> InstanceNode:
          
          try:
              return inst._entry(
                  inst.value.index(self.parse_value(inst.schema_node)))
          except ValueError:
              raise NonexistentInstance(inst.json_pointer(),
                                        f"entry '{self.value!s}'") from None
docs: Return member instance of `inst` addressed by the receiver.
  
          Args:
              inst: Current instance.