# Extra Models { #extra-models }

Continuing with the previous example, it will be common to have more than one related model.

This is especially the case for user models, because:

* The **input model** needs to be able to have a password.
* The **output model** should not have a password.
* The **database model** would probably need to have a hashed password.

/// danger

    // correct.
    this.state.markReady();
  }

  /**
   * Registers a {@link Listener} to be {@linkplain Executor#execute executed} on the given
   * executor. The listener will not have previous state changes replayed, so it is suggested that
   * listeners are added before any of the managed services are {@linkplain Service#startAsync
   * started}.
   *

     */
    @Nonnull
    Optional<Boolean> failNever();

    /**
     * Indicates whether Maven should resume from the last failed project in a previous build.
     *
     * @return an {@link Optional} containing true if Maven should resume from the last failure, false if not, or empty if not specified
     */
    @Nonnull
    Optional<Boolean> resume();

        @Override
        public Integer next(Integer value) {
          return integers().next(value);
        }

        @Override
        public Integer previous(Integer value) {
          return integers().previous(value);
        }

        @Override
        public long distance(Integer start, Integer end) {
          return integers().distance(start, end);
        }
      };

</div>

## Update the App with Multiple Models { #update-the-app-with-multiple-models }

Now let's **refactor** this app a bit to increase **security** and **versatility**.

If you check the previous app, in the UI you can see that, up to now, it lets the client decide the `id` of the `Hero` to create. 😱

`chain.proceed(request)` is a critical part of each interceptor’s implementation. This simple-looking method is where all the HTTP work happens, producing a response to satisfy the request. If `chain.proceed(request)` is being called more than once previous response bodies must be closed.

Interceptors can be chained. Suppose you have both a compressing interceptor and a checksumming interceptor: you'll need to decide whether data is compressed and then checksummed, or checksummed and then compressed....

    boolean addedPredecessor;

    if (previousValue == null) {
      addedPredecessor = true;
    } else if (previousValue instanceof PredAndSucc) {
      // Restore previous PredAndSucc object.
      adjacentNodeValues.put(node, previousValue);
      addedPredecessor = false;
    } else if (previousValue != PRED) { // successor

        // Only second directory should be invalidated
        assertFalse(entry2.isComplete());
        // First directory should still be cached (though modified by previous change)
        assertNotNull(directoryLeaseManager.getCacheEntry(dir1));
    }

    @Test
    public void testCacheExpiration() throws Exception {
        String directoryPath = "/test/expiration";

        throw e
      }
      bytesRemainingInChunk -= read
      return read
    }

    private fun readChunkSize() {
      // Read the suffix of the previous chunk.
      if (bytesRemainingInChunk != NO_CHUNK_YET) {
        socket.source.readUtf8LineStrict()
      }
      try {
        bytesRemainingInChunk = socket.source.readHexadecimalUnsignedLong()

  - [Important Security Information](#important-security-information)
    - [CVE-2021-25735: Validating Admission Webhook does not observe some previous fields](#cve-2021-25735-validating-admission-webhook-does-not-observe-some-previous-fields)
  - [Changes by Kind](#changes-by-kind-2)
    - [API Change](#api-change-1)
    - [Feature](#feature)
    - [Bug or Regression](#bug-or-regression-2)