code: def goto(self, iroute: "InstanceRoute") -> "InstanceNode":
          
          inst = self
          for sel in iroute:
              inst = sel.goto_step(inst)
          return inst
docs: Move the focus to an instance inside the receiver's value.
  
          Args:
              iroute: Instance route (relative to the receiver).
  
          Returns:
              The instance node corresponding to the target instance.
  
          Raises:
              InstanceValueError: If `iroute` is incompatible with the receiver's
                  value.
              NonexistentInstance: If the instance node doesn't exist.
              NonDataNode: If an instance route addresses a non-data node
                  (rpc/action/notification).