newLower.compareTo(newUpper) <= 0,
          "intersection is undefined for disconnected ranges %s and %s",
          this,
          connectedRange);

      // TODO(kevinb): all the precondition checks in the constructor are redundant...
      return create(newLower, newUpper);
    }
  }

  /**
   * Returns the maximal range lying between this range and {@code otherRange}, if such a range

     * only under concurrent modification).
     *
     * To access these fields when you know that they are not null, call the pred() and succ()
     * methods, which perform null checks before returning the fields.
     */
    @CheckForNull private AvlNode<E> pred;
    @CheckForNull private AvlNode<E> succ;

    AvlNode(@ParametricNullness E elem, int elemCount) {

item_id: int
```

or for a more complex `Item` model:

```Python
item: Item
```

...and with that single declaration you get:

* Editor support, including:
    * Completion.
    * Type checks.
* Validation of data:
    * Automatic and clear errors when the data is invalid.
    * Validation even for deeply nested JSON objects.

- Revised the Kubelet API Authorization with new subresources, that allow finer-grained authorization checks and access control for kubelet endpoints.
  Provided you enable the `KubeletFineGrainedAuthz` feature gate, you can access kubelet's `/healthz` endpoint by granting the caller `nodes/helathz` permission in RBAC.

  // operation (because it implements the CSI ControllerPublishVolume()
  // method), and that the Kubernetes attach detach controller should call
  // the attach volume interface which checks the volumeattachment status
  // and waits until the volume is attached before proceeding to mounting.
  // The CSI external-attacher coordinates with CSI volume driver and updates

  // 'request' - Attributes of the admission request(/pkg/apis/admission/types.go#AdmissionRequest).
  // 'authorizer' - A CEL Authorizer. May be used to perform authorization checks for the principal (user or service account) of the request.
  //   See https://pkg.go.dev/k8s.io/apiserver/pkg/cel/library#Authz

    assertEquals(s.substring(0, 1) + "ZZ", matcher.replaceFrom(s, "ZZ"));
    assertEquals(s.substring(0, 1), matcher.trimFrom(s));
    assertEquals(1, matcher.countIn(s));
  }

  /**
   * Checks that expected is equals to out, and further, if in is equals to expected, then out is
   * successfully optimized to be identical to in, i.e. that "in" is simply returned.
   */

 *  Fix: Don't drop a call to `EventListener.callEnd()` when the response body is consumed inside an
    interceptor.


## Version 3.10.0

_2018-02-24_

 *  **The pingInterval() feature now aggressively checks connectivity for web
    sockets and HTTP/2 connections.**

    Previously if you configured a ping interval that would cause OkHttp to send
    pings, but it did not track whether the reply pongs were received. With this

    TFE_Context* ctx, int keep_alive_secs, const void* proto, size_t proto_len,
    int64_t init_timeout_in_ms, int retries, TF_Status* status,
    bool clear_existing_contexts);

// Checks whether a remote worker is alive or not. This will return true even if
// the context doesn't exist on the remote worker.
TF_CAPI_EXPORT extern bool TFE_ContextCheckAlive(TFE_Context* ctx,

Without a data validation system, you would have to do all the checks by hand, in code.

These features are what Marshmallow was built to provide. It is a great library, and I have used it a lot before.