def goto_step(self, inst: InstanceNode) -> InstanceNode:
        """Return member instance of `inst` addressed by the receiver.

        Args:
            inst: Current instance.
        """
        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